I've had almost the opposite experience: reading ERB (or JSP or whatever) is a giant pain in my ass since it frequently isn't maintained with consistent indenting and formatting. I like that HAML forces that on you.
Plus it's an extra dependency and a narrowing filter for hiring.
Extra dependency that I buy. But narrowing filter for hiring? Seriously? Any web developer should be able to pick up any of these templating languages (as well as CSS preprocessors such as less, sass etc) in less than a day.
You overestimate the ad-writing and interviewing skills of companies.
And once a recruiter gets a hold of those buzzwords, it becomes a fixed requirement