Characterization is really thin, and that's usually a deal-breaker for me.

Yes! Bizarrely, I'm not sure that I could have articulated that that was (part of?) the problem in this case. Although, given that characterisation may well have resulted in a Mark Watney that I did. Not. Like, it's perhaps just as well that it was missing... (If I don't like my 'hero', then nothing can convince me to keep reading.) And, if nothing else, a lack of characterisation ended up in a much shorter book; this book would not have kept me to the end if it had been much longer as it wouldn't have been worth the time...