Regarding bug fixes in real UO: Yes they definitely need to do a better job with this. That's been consistent since the game opened. What the problem is I don't know. "Old code" is a very real thing and a decent excuse for delays and difficulties, but not like we've seen for decades now. The code was not always old. Further, if they can start from scratch to make a new shard with a separate rules set and different systems, then they can start from scratch and design systems that have fewer bugs to replace the buggy systems on shards that you know, actually exist.
However....
Regarding bug fixes in free shard UO: Dumb comparison. We're talking about smaller-scale operations who have been, from what I can tell, using the same code consistently for years. Only a limited number of pipes to worry about so security isn't going to be as much of a concern. They have a smaller customer base, one they know, appreciate, and seemingly in closer touch with. We're talking about labors of love here. They have no profit motive to worry about is my understanding. No EA legal to run things through. No EA corporate to run things through. They can just do. No one's going to ask "why spend so much time on bug fixes when our marketing studies show it isn't cost effective" and stuff like that.
Some of those free shards seem really, really great at what they do. I've seen some cool screencaps of ballroom dresses, montante swords, greater variety of tame-able pets, dedicated customer service teams, and other cool things we should have in UO and there's no excuse for us not having. But it's not a fair comparison.
Pointing this out doesn't excuse the UO team from their foibles (though I know the more-competitive among you will likely think that's what I'm saying), but it does mean that we should stop comparing big apples to tiny oranges.