As a guy, I've gotten compliments from het men plenty of times, and there was never any confusion about whether they were hitting on me. And I'm in the military, and it was coworkers most times. "Nice haircut, where do you go? You do it yourself! Wow, nicely done!" "Nice shirt, looking good! You got plans after work or something?"
I am not a particularly attractive guy, either. I really wonder what circles all the guys that either don't get compliments or get awkward about compliments (like in this comic) run in.
Still a funny comic, not a criticism. Women are definitely way more open with their compliments to each other.