MilSim is pretty much impossible as far as CM goes, in terms of meta, timeframe, and playerbase. LRP is possible, but I think it's generally undesirable. MRP is a good middle ground IMO.
Regarding Commanders specifically, I think we're in a position where we can hold ourselves to higher standards of RP -- but I also don't think "meme" or otherwise silly COs should be ragged on too much for taking a different approach to things. We've all got our different ways to play, and so long as it's not harming anyone, I don't see any issue with it.
Personally I bounce around. There are times when I'll act a little sillier/cartoon-ish and there's other times I'll put in some solid RP. I probably would feel a little limited if I had one of options cut out from under me. We should be versatile with how we play and be able to respond to the situation in the best way we see fit.