I think at the time I was still in the mind state of 'assembler is best for everything' and this made sense, since I was far more fluent in assembler than C. If you have developed an infrastructure around working with asm and have a lot of general purpose library style src code from previous projects, you can often get things working as fast as programming in a hll. Projects were often much simpler then as well, memories space was smaller and processors were much less pwerfull.
Having said all that, I wouldn't consider asm for any project these days, other than startup and maybe some interrupt level code...
Chris