Just don't like C, to me there is no point in mixing the two (C & Assembler) as I only write stuff for the Amiga and have no interest in any other platform then to me coding in 68K is the best way to go as I don't need to have code that can be easily recompiled for use on another platform... 
(Plus to me coding in Assembler on the Amiga is far more easy than any other langauge... 
I used to advocate the Assembler a lot, few years ago. The I switched to C and still use Assembler, but C is better for the following reasons:
C is universal - no matter if you write for CP/M, Gameboy, Apple II, Amiga, AmigaOne, Windows or Apple Mac. The C syntax is still the same. In some cases you even use the same compiler. I have coded for all these platforms in C and had much less troubles than when writing for these platforms in Assembler.
C is high portable. I wrote a game eight years ago in C for Amigas with 680x0 processor. Later I easily ported it to Amigas with PPC processors, Apple Macs and Windows! I can easily port it to IPhone, Symbian, QNX and Linux if I wanted to. If it was not in C, I would had a hard time porting it in to all these platforms.
C is easy to find. You can easily find books on C and no matter if it is for Windows, you can learn from it for your Amiga programming projects.
C is very close to the the Assembler. Its so close that you can easily skip assembler and go for C and have the same programming power at hand, only easier and better.
C is easy to spell. You can not misspell it like the asssembler.