Adrian doesn't seem ashamed, but he does seem cautious and concerned with the pleasure, well-being, and fulfillment of his partners. Shouldn't he be concerned about those things, invested in them in a non-egotistical way?
It's a really weird reaction to a suggestion of being dominant in the bedroom to be like "yeah, male tops, terrible, amirite?" Now, admittedly, the default state of men in the SJI universe seems to be morally bankrupt and the default state of women morally immaculate (exceptions for Adrian and Cherry, though whether Cherry's general nastiness was entirely the result of MC is up for debate), but I don't think that the comic is supposed to depict a world where that is true as a contravention to the real world. Adrian isn't really known to have male friends or associates; this is erotica, meant to portray a harem-type relationship with supernatural mind control, so it makes sense that the focus of it is on the main character and his female companions. But it comes off as... sort of territorial in a sneaky, underhanded way for him to make comments like that. If you've spent times in BDSM circles you've certainly met cringy male tops... but w/e, it's their life, as long as they aren't hurting anyone. But I've met cringy AF female tops too, and my attitude's the same.
I guess it looks like, from the outside, that Adrian has this emotional need for female attention/approval that's kind of... codependent/unhealthy. And he seems hung up on the idea that most other men are terrible, or at least he's trying to impress that upon Erin. It comes off as Adrian having not really "left the cave" in terms of his development as a person. Essentially, Adrian doesn't really act, he mostly re-acts, and he mainly seems to serve as a facilitator for the members of his "harem" to do what they were going to do anyway. I really do wonder what Adrian actually wants, like what were to happen if he were to plan an evening of debauchery, for example, instead of the women planning it for him.
