I don't think it's a mistake to point out the hypocrisy of criticizing a man for magically compelling women into bed while you're getting into bed with magically compelled women. The protagonist is a kinder, gentler master than his father was, but it remains to be seen if he can maintain that fragile moral high ground when time and power have had a chance to corrupt him.
I think it's a matter of what the moral environment of the story is. All stories make certain assumptions about the value system that they are set in. In a way, worrying too much about whether MC is intrinsically evil in an MC fetish story is like worrying about colonialism in an H. Rider Haggard story.
While that's a good point, MC is intrinsically evil in the societies in which we are all embedded... both historically and currently (golden rule and variations thereof as evidence). But as a good friend pointed out, as long as you're going to fantasize, you may as well make your fantasies perfect as you can.
Any mind controller worth his (sorry; for me it's almost always "he") salt will make sure his thralls *love* being controlled. And who is to say if, in the context of an MC society, that that's any worse than, say, and effective ad campaign for some other lifestyle modification, e.g. a gym membership?