Every single one of these topics fails to explain the only relevant things:
a) how has the game changed;
b) how do these changes make the game less fun/more frustrating?
Even taking into account all of the major changes together - Rift Update, visible spawn timers, new items, messing with death timers, turrets, dynamic queue - it is unclear that the game is significantly different (the core gameplay is untouched), and why these changes would make the game less fun.
Also, players have been leaving at all stages in the game's past - my friends list from season 4 contained less than half of the people from season 3 and every following season has been the same. This does not tell us anything about the quality of the game, it is just indicative of gaming in general. If you play a computer game, you are not tied to it the way you are to an athletic or academic discipline. The cost of switching games is very low, the rate at which new games come out is very high. Stop thinking this means anything,