Actually, only half the bots on a server will show up as players in UT2003. Typically if there are 3,000-4,000 players, about 400 or so will be bots.
The Gamespy stats can be misleading. Some games will rise and fall dramatically depending on the time of day. Both UT and UT2003 experience this, peaking near the top of the list and falling near the bottom during their low points of the day.
id Software does not own the copyright on gothic castles and similar imagery, but I suppose since they did it first, people will forever accuse other companies of ripping them off. Gothic castles and demonic imagery existed even before Doom and Quake. Shocking, I know.
Schnapple is bang on with acceptance. A lot of people are very reluctant to give up on their favorite shooter and try something new -- this seems especially prevalent with the DM-style games like Quake and UT.
If you don't like UT2003, that's fine. I think it is flawed but still quite enjoyable. Double Domination is a terrifc game type. I don't see the need or value in insulting people who do like the game, but I suppose that's part of the whole trend toward unfettered hostility that is the Internet.