But why did Vince align with Austin at WM X7?

I agree with you 100%. I believe Austin said somewhere that he came up with the WM X-Seven turn because he thought he was getting stale and he thought he would get incredible heat and Rock become more over. He was very wrong as the fan approval ratings didn't significantly change and just seemed like they were confused more than anything.

Then him siding with the Alliance made absolutely no sense. Why would the guy who was fired by WCW and the driving force in WCW's loss in the Monday Night Wars, side with them? It would have made more sense if either Big Show, Jericho, hell even the Rock to side with them. The thing was that the Alliance needed a big name and with the all the original members of the nWo, Sting, and Goldberg riding out their AOL contracts, it was a short list and almost immediately WWE killed the top prospect for the role in Booker T. Angle worked as the traitor as he was really over but still not over enough that the fans would turn on him. I think the reason was that Vince was tiring to have Rock become the face of the company at this point and the only way that wasd going to happen was if Austin became the top heel. Unfortunately for them, the fans would continue to cheer for Austin anyway. By the time they were finally able to do it in 2002, both guys were on there way out and they had lost a lot of fans because they didn't like seeing Austin fall so far so fast. This is where I don't like Rock fans, they think that wrestling's decline in 2002 was because it was getting stale. While that may be true, it seems more likely that it was because they were forcing Austin's fall from the spotlight. There was a reason Hogan chose Rock instead Austin and that was because the Rock didn't pose a threat to his legacy as the Greatest of All Time. WM X8 had a significant drop in buyrates.

I'm pretty sure in his documentary he said it was a horrible decision, because of how popular his character was and if that he could take anything back it would be that moment and instead he would of gave Vince a stunner.

Looking back, I wonder if Austin knew that would be his last full year of active competition. Maybe he felt like having one last run as an actual "heel" before he hung up the boots.
I really felt he hearkened back to his WCW days around that time, and that's the only thing that made sense to me, especially during the Invasion storyline.
Maybe that was the plan all along. Didn't Vince purchase WCW right before WM17?
Maybe a Hollywood Blonde-Early 90's-Cowardly Heel-Stunning Steve Austin seemed perfect to lead a WCW Invasion at the time.....

Austin stunning Vince at the end would've been equally stupid. It would've been one swerve too many and confused the audience once the initial pop subsided.

I still think an Austin heel turn could've worked. Its difficult but with great risk comes great reward, and if they'd done it right (very different situations but Hogan is still the obvious example) then it could've been massive. Personally, I'd keep WM the same but the next night start teasing Austin is already unhappy with Vince and HHH (who helps him win the cage rematch vs. Rocky). Increase the teasing for a month or two then have Austin turn on HHH when facing a tag team, perhaps Jericho/Benoit or the Hardyz. Next PPV Austin gets to choose a tag partner to face HHH and Vince (who deludes himself into thinking he can beat up Austin because he's so mad he's been played.) He picks an over face (Jericho?) and acts a face again. Then they beat HHH & Vince but Austin stunners Jericho. They then play up the whole 'DTA = Don't Trust Austin' stuff that they used in the invasion (the only good part to come from that horrible turn imo) and he screws people left right and centre. Him and Jericho could go into a feud that could elevate Jericho and ends with him winning the WWE title. Austin is pissed but puts aside his anger when the invasion comes to town. He teams up with Jericho and other for the 5 vs. 5 where Jericho turns and joins WCW, making Austin face again.

Alternatively (and I think this would be more interesting), Austin is asked to fight for WWE against WCW but refuses because of the lone wolf stuff he's been pushing for the last few months. WWE constantly ask him to help but he goes around feuding with anyone and everyone on both sides. This culminates at the Survivor Series 5 vs. 5 where Rock stares down the WCW top heel, and Austin comes down and stunners them both. He could lose in the championship battle royal at Vengeance, before losing to Rocky at RR (with these consecutive losses showing chinks in the Austin armor). Then the NWO come into town, and Vince wants them to hurt Austin as well as the WWE as a whole (lingering resentment over their previous feud and his refusal to help when the WWE needed it). They all beat on Austin and Rock and tell Austin how a team will always work together better than a lone wolf. Him and Rocky get beaten up week after week and by No Way Out they're booked in a tag match vs. Hall and Nash. Austin says he refuses to team with anyone and doesn't come down and Rocky fights alone. Rock puts up a huge fight and might actually win but Hogan interferes and costs him the match. However, as the NWO celebrate Austin comes down and cleans house before helping Rocky up, cementing his face turn. Hogan and Rocky branch off for their match, whilst Austin is forced to team up with someone against Hall and Nash to prove he doesn't always have to be a lone wolf. The partner should just be an over face - RVD maybe? If HBK was ready by then I'd get him back so he could team up against his old foe. They'd win but HBK could superkick Austin the next night and join the NWO, and Austin could feud with them through the summer.

whatsaspacebar?

but,seriously,we all make grammatical or spelling or punctuation error's from time to time. hell,I made like 3 or 4 this morning already! big deal! we're typing fast,mistakes happen.

I'm not "giving Joker a free pass". I'm just curious as to why your first post in this thread is about spaces rather than actually CONTRIBUTING to the conversation going on here?

it never made sense man.....I don't think the reason was revealed on TV either....as in a concrete reason as to why Vince aided Austin?I was so horrified by the product at the time I wasn't watching.

Vince sees it as if Austin is with him, then he's not making his life hell, Vince gets Austin to stop tormenting him and Austin gets the wwf title.