What the hell happened between now and then?
Developers/Publishers discovered that if they let players share their own content then additional content they want to sell in the future (aka expansion packs) have more competition and have to either sell fewer copies or drop the price.
People who purchase games are a commodity to be exploited, not competition to be nurtured. They don't want lots of free content. They want only their content that costs money.
DICE had fantastic support for BF1942, BF2 was largely built on the backs of the Desert Combat Mod. That probably didn't make them too happy that their road to rome and secret weapons expansion packs got ignored in favor of a free mod called desert combat.
BF2 has pretty good support for mods but the subtle changes made it much harder to get people interested in free content and I don't think anyone is touching BF2142, certainly not BF:BC.
Free content is competition for them they don't want.
It would be if they intended to keep selling their products but they want to spend millions of dollars making a new game then sell that for $60 instead of trying to get more and more people to buy copies of an older game.
It's all about Hype. Hype sells. Hype sells A LOT of shit. And it's cheaper to sell shit and keep people buying it than it is to support and grow a good product year after year.