By and large I'm a fan of the changes to daily achievements in GW2. Personally, I hated having to do the “mob variety” every single day. However, things haven't got much better: annoyance has been replaced with other annoyance.
Surely ANet would know that if you log on in, say, Orr or Kryta you're going to see more undead and centaurs than anything else and that you'll need to go pretty far afield to see anything else. That makes kill variety tough.
Underwater kills? I might have to go to an entirely different zone.
The worst, though, is Daily Healer. There just aren't that many dead people around. I guess the point is to encourage you to rez players, and to encourage players to wait to be rezzed, but I do that already.
That's not what it's supposed to be about, is it ANet? You don't want us to go out of our way to get this done do you?
Having a bunch of Alts helps. Daily Dodger is very easily achieved with a Death Blossoming Thief and stationing a character at the Thaumonova Reactor is a great way to do Kill Variety.