The ironic thing is I actually did make some small games in C for DOS years ago, then I was employed doing C/C++ for several years. So I apparently know the language well enough to have a job doing it, but on NES I just couldn't get used to it. I think I ran into at least one situation that I really had no idea about. Like, something in the cc65 compiler was stepping on variables I was allocating in my sound engine or something like that, and I couldn't figure out why. There's just so much noise like this to worry about. Doing C on a PC you rarely have to think about the actual linker configuration, on the NES it appears necessary to understand these things really well. Which I do, in pure asm. With cc65, it's like I suddenly have to understand the compiler itself in order to use it effectively. That's how it felt to me, irrationally, in any event.
I think the key phrase there na_th_an is that you like to fight the compiler to get the most out of it; I found this act too frustrating; I'd rather just write the asm code. By the time I was done wrestling with the C compiler I would have written the asm anyway, haha!
*Edit* I'll have to say though to answer the OP: I keep seeing amazing homebrews made in C. I don't think it would be a compromise, especially since you already know asm and can use it to get over performance issues.
It really boils down to whether you're interested in the language and enjoy working with it on NES. So I'd say give it a try for a few months like I did and you'll quickly find out whether you like it or not.