I've seen a lot of, well, ...inexperienced WhM's, but it's very rarely the Glare bots, it's usually the healbots. They follow the same pattern, 1 Presence of Mind on the pull then ignore it. 1-2 Benison the entire fight, no asylum, temperance or Plenary, Assize only used to heal and buckets of Medica II's and Regens. The glarebots are usually the ones optimizing their class and besides an occasional stubborness on hardcasting raise (sort of like a silent battle of healer willpower to not be the one taking the job) they've been mostly fine in my experience.

Healbotting is definitely something I see 80% of the time (at least). Especially when I started playing AST. AST healing for example isn't reactive like WhM. You have 2 oGCD HoT's (Diurnal), wait time for Giant Dominance on star and ED is better value if you let the tank drop a bit. The group is in no danger waiting on any of these heals or letting HoT catch up, because raidwides are rarely in quick succession, but you can almost guarantee your co-healer is raining raidwide heals on the party like confetti.
I sometimes wonder how they're feeling during this. Are they, like the OP, sitting there going "wth this AST doesn't heal raidwides and the tank keeps dipping below 50%, I'm doing everything here!" as they snipe heal after unnecessary heal and turn thousands of my heal potency into wasted overhealing? "Look, he's just spamming dps and we're dying!" as 2 oGcD's are smoothly weaved in for a double HoT that's immediately wasted by heal spam. Who knows.