I am usually trying to not be too much of a fanboi but I feel I have to stick up for HoT here. Thing is, I felt the same hate when I first entered HoT, after having a blast in the original.
It was like hurdles to the fun had been thrown up in so many ways: hugely confusing maps, lots of movement mechanics behind achievement locks like gliding, jumping shrooms, Wallochs and last but not least, lots of tough mobs everywhere that just love to cripple you so moving around becomes even more of a pain.
So I almost never made it to the moment where I could even just glide. I can not really remember how I trucked through to the point where I started enjoying the Vertical maps and the events, but gliding had a lot to do with it. You get your first Mastery point that learns you how to glide pretty fast, btw. And then the "Masteries, must collect them all" bug hit me, and in the next 3 months I "finished" HoT, including having made Astralaria. I have max Mastery points exept for the 8 that you earn with the Raids. I also am missing a lot of achievements like a lot of Gold medals for some of the MIni-games, but getting Bronze and SIlver for those was actually a lot of fun.
So once you unlock Gliding and some of the first map, then a few Masteries and off course your Elite spec, it may still pull you in. I do not even like my Elite spec (Druid) so never used that anyway. But I also enjoyed how I managed to become better at beating those mobs: the old world had become rather easy, even for a mediocre player like me. So in HoT I can feel like a (PvE) boss (I know, it's sad).
I will not say that HoT is now my favorite place to be: it is not. But I definately go there from time to time and join a Meta. The stuff you earn there is still valuable (Legendaries, trinkets that use HoT currencies, lots and lots of regular loot during Meta's) And off course it looks cool to have that 185 number next to your name (your Mastery level).
(193 is max when you also do the Raids and earn the Masteries there)
My playstyle: PvE is my thing and the thing I enjoy most is doing the Collection quests for all the precursors of the Legendaries, which take you all over the world and have you do lots of different stuff. (takes you into WvW too btw. )
I agree though that HoT has a different vibe then the old world. It is not nearly as relaxed, especially for solo, very hectic maps and really only fun if you join a group/zerg to do some events or Meta(after you have gotten all out of HoT when it comes to Masteries and Achievements).