Not really, one of the hardest skills to learn in DOTA is how to react, not how fast you should react. Often, not helping your team can benefit the team.

I'm immortal ranked Dota player, that spends 10 hours a week playing Dota. And has played DOTA since Warcraft 3. My reaction time is slow, because I think so much about each situations. And a slightly bad decision can lose the whole game. When I see my team fighting, I take a short look, maybe think for as long as 2-3 seconds and make a decision about if I can contribute to the fight or if I will just be feeding.

DOTA is a lot more about strategy, positioning, how to pressure, farming patterns, vision/warding, when to use power spikes and be a team player. This is also why experienced players beat the crap out of younger players and probably also why younger players play something else than DOTA/MOBA.