1.0 had a lot of problems during it's start, for example the combat system was changed several times from having to execute your basic attacks to suddenly have auto-attacks. Also the exp system was confusing, given you exp for healing someone not in your party and having a reverse rest system when your exp gain suddenly plummeted sharply unless you changed to a different class.
Back then leves when the name of the game for exp, but that also got changed a lot. I recall being able to handle lv 20 leves on my PUG15, but suddenly it was changed and now I had to do lower level leves for crappy exp.

What drow me away were all the different changes, it felt like they didn't have a clear direction for the game back then and it felt imcomplete, like questing getting patched in later and wasn't a part of it from the start. I did love the very big open worlds, I hope they get more programmers and money to this game so we can have truely big maps like in 1.0(but with less copy paste locations)