Thanks Mr. Obvious. Ive been a logic user for six years and I am fully aware of what faders and compressors do.
your question
did come across as quite newbie, and it is the sort of thing that a lot of new users do ask... it's easy to misconstrue where someone is coming from on this forum especially when they don't give any details in their question that indicate any specific knowledge about the area in question.
Does anyone else have this issue?
I personally wouldn't even consider it an issue.. modern DAWs are designed to deal with input sources as variable as they come. add this to the fact that they can also generate so much extra gain when you start using piles of plug ins, typical of modern production, so having headroom to spare is not an issue.
also, some audio instruments are going to have a broader range of base levels just by their nature - the EXS24 especially. the output level of a sampler is always going to change from sound to sound depending on the personal taste (or laziness/dilligence if you want to look at it that way) of the person that built the sound.
other instruments just have arbitrary basic levels, probably set that way to allow for the ful dynamics of the instrument to be available without clipping too easily. adjust them either with their own volume control (if they have one) or just use a gain plug in. also, make sure you haven't accidentally sent midi volume or expression control data that is turning them down.