I haven't been doing this too long, so maybe my response will sound like I'm smoking crack (which I'm not), but I think hermits are essential. They are a clean up crew that take care of extra food lying around that your fish don't eat, they trim back algae and waste and stir up the sand bed. I have no idea why someone wouldn't reccomend them unless they don't get a good price on them or can't seem to stock them too well.
The only thing you may want to watch is what type of hermits you use. Though I have both scarlet and blue legged hermits with no problems, I believe many people shy away from the scarlets due to aggression. Again, I may be wrong about the species, but that's what I recall.