you know what's annoying? when you are trying to get someting done and then "boom" please backtrack all the way to the nearest city and get your HM slave please
I know that feeling. Luckily, I replaced my Carvanha that had Dive, Waterfall and Surf with a neat and bulky Milotic.. and yeah, my Blaziken still has Rock Smash.
But then again, it's not like sacrificing coverage for a HM move makes the game unplayable. Regardless of that, it's still annoying.