It was so much worse before Forge. With Forge, it's still incredibly arcane, but it's not batshit crazy like it was before. Of course, now you need to have the Forge version of a mod, and you have to have the right version Minecraft too.
I'm getting mad just thinking about it. I need to stop now.
This also highlights why client side mods (Forge based or not) are the vast minority of 'Modded Minecraft'.
Configuring a Bukkit server would still have taken some work, but it also only required that to be expended on the server side.
Players would be able to connect with a purely vanilla client and benefit from the enhanced interactions and gameplay mechanics that could be handled on the server side only. This attracts thousands more people than fiddling with launchers, or worse, .jar files.
I'm getting mad just thinking about it. I need to stop now.