If a product is shipped with a 90% full ROM instead of 50% it is OK. If Another need a bigger part but is finished quicker may save money on a same volume part.
If a programmer use every bell and whistle in C and make a big slow program, that is his problem, not mine. I use C, I like C. If some yahoo nails his fott to the floor with a nail gun does that mean carpenters can only use hammers? Do they need to use hammers for a few year before they can use the gun?
I like that I can reuses c from one CPU to another. Do PC programmers who want to do an 8bit micro in C ( becuase they can not find C++) Code a train wreck? Absolutely.

Year ago I helped an ASM programmer learn C after a few programs he would look at the compiler code and said some times I would be better than the compiler, other times it was smaller then he would have done.
an good ASM program given enough time will away beat the Compiler. But that time is money too.
Being a Good C programmer is often enough.

C code being 300% bigger then ASM is a VERY Old wives tale. ( Assuming a good compiler like Keil)