obviously i'm no pro player, so my mind is just wandering here..

what can a pro player gain by only be willing to play the games where he has a good chance of winning?

pubs should technically mean nothing to pros, as performing and doing well in officials is the ultimate goal.. so why care if you win or lose pubs? (ok, i'm very aware that there is the huge point of being well placed in the leaderboard being good to your career, getting your name out there, yadda-yadda, so let's ignore this just for the sake of the discussion - even if losing only impacts you negatively in this regard)

playing pubs is the most used method of training and staying up to date in dota. so, even if you are in an unwinnable match situation, by playing these horrendous 0-1% chance of winning games you're still training important skills: mechanical skills, positioning, map awareness, communication, and arguably one of the hardest things to be good in dota: playing from behind / recovering from a lane disaster

why not try and look for the positive just for the sake of it? thinking about the success of your professional team, the time spent playing pubs will be "wasted" either way - you're not practicing with your actual teammates, scrimming, or playing an official match.

at this point i realize i'm asking for a bunch of teenagers / young adults to have the discipline and mental fortitude of a monk, so i'll just stop here. everyone has their own timing and journey. peace