Here is the point you missed
if i want to play 6.83c fixed map i prefer icecup
if i want to play 6.90a8 i prefer lagabuse
if i want to play 7.03-04 i prefer rgc
It's stupid to think that people will stop playing v6 and switch to v7, as you can see, custom maps /v6/ are being create at night, or there were people who switched to rgc.
For myself, instead of choosing the current dota 2 version in the current dota 1, I switch to d2 better.
Having played all versions in all communities, I think the most enjoyable version of the game is version 6.9. There is a bug situation, of course, the fixed version of it will be even better, like icecup. Also, no matter what version, there will always be a meta hero pool. Let's not confuse this situation with heroes with bugs, please. This should not be difficult to understand.