People said this about Legion too pre-release. A lot of people didn't like that you had to unfreeze the enemies and then kill them again. Some people didnt like Breach either because you had to wait for monsters to come rather than then spawning all at once.
The bottom line is simply how rewarding this league mechanic is. Players will spend an additional minute or two if the returns are there. That's why Legion was so popular, the chests had superb drops.
That said, I think the major limiting factor to this league is the fact that so far we haven't seen any Rares pop out of these Blights. That is a massive nerf to Headhunter if you want to engage with the league mechanic. That's probably how they plan to balance the mechanic so that players with souped up HHs and supports can't just demolish the incoming enemies without even using towers.
Nah, I did not get the feeling at all from Legion. But I agree with you regarding rewards.
This league was a mess for me because I found a Headhunter in week two, sold it for 80 exalteds (or close to that), fully geared a Cyclone char with the money and lost all interest in the game, and spent ALL the currencies wastefully. That process I did enjoy though, as I made several self-made chars instead of cyclone (like a chain spectral shield thrower who sucked on bossing, and then tried out pure flameblast which utterly, utterly sucked, and then tried out Arc totem FOR THE VERY FIRST TIME (I hate fotm builds :P)....)
This time around, I'm going to self-make some non HoA-poison minion builds or have one more go at an SRS summoner.