Not to beat a dead horse, but if you really believe that the FIA cares whether Lewis Hamilton wins a sixth championship, and is willing to unnecessarily intervene in such a manner, you need to work on your critical thinking.
Unless the FIA are somehow forcing their guest stewards to intervene whenever possible, which is nonsensical, how could they even begin to control the outcome of any given race, and why would they choose Montreal to intervene? Both Lewis and Mercedes have the season locked down already, and to knowingly, and so unnecessarily, precipitate such an outcry would be madness.
And does the FIA even make more money with a Mercedes victory? I can't claim to know they don't, but neither can I easily envision a scenario where they would. In fact, Mercedes' dominance, especially their recent dominance, has probably cost F1 numerous viewers, and while I doubt that necessarily affects the FIA financially, I imagine their self interest is best advanced with a healthy F1.
The likeliest explanation for the penalty is also the simplest; the guest stewards, all of whom are either current, or ex-racing drivers, probably didn't want to decide the race any more than the racers and fans who so vehemently condemned the penalty, yet saw incontrovertible evidence of Vettel's culpability.
At that point, they're compelled to uphold the rules, not use their subjective discretion to decide what's best for the race, or the championship, or any other externality one might consider.
I wish they'd simply made them swap positions, with Vettel able to regain the lead in the closing laps, but perhaps that wasn't an option. If that's the case, hopefully it will soon become one, but regardless, a penalty was almost certainly deserved.
I thought the penalty should have been for leaving the track and gaining advantage, as I'm not sure why Vettel's intent should even matter, but he almost certainly did what anyone would do in that situation; the moment the rear was back under him, he was hustling to make sure he didn't lose his lead.
I'm not sure why so many are ignoring so much evidence in favor of their immediate, emotional reactions, but absent any actual evidence of a stewards' mistake, let alone FIA/steward bias (and no, alleged inconsistencies aren't evidence of bias), neither explanation is reasonable.
