Honestly, people who never had issues with too much latency don't know what they are talking about when they say "you're just bad", "learn to evade", "get a better connection".

Yes, the connection can be bad. Should you have to use an additional service to reduce latency? I'd say no.
There are plenty of games out there without these problems. Games that require quick reflexes and where you have double the latency because your target is not a mob on a server, but another player.
Running around the whole fight is no solution either.

How do you evade an attack which is almost done casting before it even appears on your screen?

I had problems evading attacks before SE increased the number of calls to update your current position (down to 200ms from 300ms if I remember right).
If I didn't move the moment I saw something on the ground, I would get hit, even if I was out of the damage area long before.
Now? I'm doing Titan HM for fun and to help others and I rarely get hit by Weight and never by Landslide or Bombs, no matter which class I play.

So, it's clearly in SE's power to reduce connection-based issues.
I'm not saying this will solve the problems for all players, but there clearly is room for server side improvements.

And I've yet to see a game with a requirement like "minimum: requires a ping lower than 50ms to IP xxx.xxx.xxx.xxx".