They're right to complain. It's just too common to see people with mana drain...because it's almost for free, just before linebreaker.
It's already a great CC on itself, but I don't know why they added drain and rending strike on the way to linebreaker. It just makes it a way better thing to feat than the other end tree feats.
Just the fact 99.9% of people go for linebreaker on rangers is enough to prove that something may be wrong.
And those who don't, doesn't do it because it is efficient I think, but to try something different or because they have more fun with other things. Linebreaker is the most efficient tree and erase all the other. It would be better if there was more balance. I recently tryed the distance fear end tree...I loled. The dps of that "combo" is less than quick shot !!! LESS. While linebreaker has same dps as penetrating shot. Ridiculous.
"Let's give this end feat tree a powerful dot on every advantage, great dps on an already great CC, and well, let's put some drain traps just before too. Now people don't have to think at all when they create their feat".