Well it's fairly obvious they ruined the game for the majority of UO veterans with the expansions and publishes. There are so many reasons, here are some of mine...
I preferred the game when it was more simple in regards to weapons/armour, I remember when items didn't have all these numbers and stats on them and I always thought this was a lot more immersive. A katana was katana. Click it and it said katana lol. Now when you click it you get a whole load of junk that just gives me a headache and reminds me of other RPGs. In the current UO 1337 stats on your weapons and armour mean everything. And this just breeds a horrible community I'd rather not associate with.
Next, expansions and the new lands. Even the T2A land mass was pretty worthless IMO. They got worse with each expansion. I can't remember a time when I was playing that I actually enjoyed playing in these new land masses. I only have good memories of Britannia, the original and best. Basically these areas just put me off the game, even when I didn't go there lol. Another bad thing about the expansions is all the garbage they throw in to get new customers (I guess its kinda working for them though since they keep doing it?), such as the 3D engine and the SE expansion etc. Yeah EA definitely cater towards new customers instead of old ones.
I don't have to mention Trammel/Felucca lol. I still can't believe they changed that as it was the best thing about the game having free PVP as it created risk and challenge. I remember reactivating my account a little after Renaissance came out and confronting some miners with my friend, and then we tried to war them and nothing happened lol. They just laughed at us. It went downhill ever since that moment. Now I only play on OSI to find bugs and mess around with the n00bs which is actually a lot of fun.
As for RunUO it's great, a big improvement from the days of UOX lol. I don't really play on PR shards much (never found the right one really, but IPY came close I guess). I'd like to create my own shard, just gotta get rid of all the trammy stuff from the current RunUO distro and I'll be set.