I understand that if you are/were already a TF2 player, the switch to Overwatch seems natural, especially considering the fact that, altho being popular, TF2 doesn't have any major LAN event(s) and is playing mainly by casual or hardcore gamers, but not really by "true pros" players. I think it's fair to say that OW has a brighter future than TF2, and on top of that, is more "complex/strategically demanding", and finally, OW is fresh, new, and made by $$$$$$ BLIZZARD.
Both games share a lot of similarities, I think that OW can even be called "TF2 2.0", to be honest.

However you will probably ask me, "then who are those infidels, traitors, money addicts, fame addicts ?". The answer is simple : Quake players. And I was one of them at some point, but not anymore, luckily God oppened my eyes and showed me the right path : continuing to play QL/Reflex until Quake Champions or Diabotical come out.

OW is NOT Quake, if you are a true Quake player then stick with it and support the game no matter what. You can play QW, Q2, Q3 CPM, QL, Reflex, it doesn't matter, as long as it's QUAKE or a Quake rip off.
90% of us grown up playing Quake; Quake isn't only a game, it's a life-style; Quake does have the most beautiful/epurated/skilled FPS gameplay ever made. OW on the other hand, is a game full of gimmicks, imbalance and lame gameplay features that have no place in a true hardcore FPS (which obviously OW isn't).

Let's be honest, at least 80% of the Quakers who switched to OW are just in the "HYPE train", they play it not because they like it more than Quake, but because the game is very popular, new, and you can earn money by playing it, unlike Quake at the moment. But the reality is that they are, pardon the expression, "fucked into the ass by BLIZZARD". At the end, it's a WIN/WIN situation for BLIZZARD and WIN/LOSS situation for the Quakers playing OW, but they will eventually realize that only at long term, if they keep playing it...

At least people like evil or rapha didn't miss the last QuakeCon, so props to them for that.
Don't lose your faith in Quake, no matter what happens. Once a Quake player, always a Quake player.

But Lord has mercy, so hopefully all those quakers playing OW at the moment will eventually come back when Quake Champions or DB will come out, and finally follow the right path again. God will be like "Welcome back, my sons".