The crash didn't wreck Massa's career, having Alonso as his teammate did, Massa is at the same level anybody else (except perhaps Vettel) would be if they joined Ferrari.
Hmm, but there's more to it than that - Massa just doesn't seem to be able to:
1. Fight the mental battles against Alonso.
2. Display the speed to prove he is capable of beating Alonso.
3. Get the most out of a terrible car.
If it was just a matter of #2 status and being asked to move over for Fernando, surely Massa would have some podiums or wins when Alonso wasn't able to or retired?
The problem is Massa has rarely been in any position where team orders were required bar one special incident in 2010. He has rarely ever been ahead of Alonso so that he is needed to move out of the way.
One race in 2 and now looking like 3 seasons? Yeah there is more to that than simply being teammate to Alonso. Fisichella and Trulli managed to be ahead of Alonso on occasion and I don't consider those two mentally strong.
If Ferrari produce a stable and preditable car, Massa will be closer to Alonso. But as long as Ferrari keep producing average and unstable cars, Massa will struggle to get the same speed and consistencey as Alonso. I'd also say that clearly Massa isn't the driver he was in some respects (or he is wholly reliant on a decent car) because even when the car was pretty good in 2010 - Massa was still regularly behind Alonso.
Sorry guys but simply having a dominant teammate and team-orders doesn't make you slower all of the time - it simply means you have to move over from time to time and suffer from poorer strategies. But if a driver is good enough, he will still be able to shine and 1-up the status quo every now and then.
Schumacher's teammates regularly had blatant team orders and restrictive contracts but they still managed to beat him on occasion.
With the right set of circumstances, Massa could have been WDC. But this applies to almost every driver on the grid today. I think a mixture of issues have caused Massa to fall into a deep hole which he only continues to dig the more he screws up trying to make up lost ground. Sadly for him, he will seemingly be only remembered as a driver who once again made Alonso look good rather than a driver who almost achieved a WDC.
Massa has never been a top driver but he is/was pretty good. Inconsistencey and a lacking mental capacity as well as cars that don't really suit him have led to the poor results. It also doesn't help when his most successful tracks (e.g. Turkey) are taken off the calendar.
Give Webber the same contract and opportunity as Massa and I guarantee you he would on occasion out-qualify or out-race Alonso. Or Perez, Kobayashi, Rosberg, etc. Thats all anyone really expects because consistently beating Alonso is pretty much proving WDC ability - and I don't think anyone expects Massa to beat Alonso over a season even in his top form.