"There were only like 7 maps compared to the hundreds available for 2k4, less gametypes, less fun. Less support for mods, too."
2K4 absolutely did not have hundreds of maps out of the box. The only reason 2K4 had as many maps as it did at launch is because it contained the maps that were made for 2K3 as well. Completely unrealistic to expect as many maps in a brand new game.
Doesn't matter if it's realistic to expect more maps, the fact is the older game had more maps to play on. "Hundreds" and "7" are both hyperbole, but UT2004 probably did have 100 more maps available to play than UT3 did. Many were 2003 and 99 maps, but that doesn't matter. If UT3 hadn't gone so far off the deep end in terms of art style, they could have redone some of the textures and branded them "classic" maps (to make up for any complaints about inferior appearance) and called it a day.