All things being equal Bioms O plenty might be a better mod than Extra bioms. But we can't simply remove Extra bioms as that would trash all existing worlds. And we can't add it as well as that would create way to big a mess.
Actually, you can! See, the author evidently realized this could happen and what he did was make it so that new worlds set the default level-type in your server.properties to a special type to get Biomes O Plenty. You can install both mods and they do, in fact, work. Meaning that people using ExtraBiomesXL in a pack with both will not be penalized, but people starting new worlds can get more biomes.
I sort of don't understand what happened with BoP's author and the ExtraBiomesXL team. I sort of don't care. What I do care about is the sense of adventure I feel when walking around my minecraft world, and I know that BoP really does this for me. They have some really great worldgen in that mod.
Also I read nothing in that addon plugin about bees IC2 rubber trees or a number of other bioms specific addons.
They spawn in all biomes.
And another thing why did you say "we're not allowed ot. Surly you're not advertising your own mod. That's just in bad form.
I do not know what you're talking about. I say, "We" as "We as the community of players and developers." Mod developers are just players who know more about programming than the average player, but we're all part of the same community.