I agree that it stems from insecurity and low self-esteem. Fear of loss as well. A partner may be the jealous type and be afraid that his/her partner will leave him/her for someone else, which is less likely if that partner is made to feel grateful that the abusive partner would be with them at all.
I do also agree with the vicious cycle thing. It's not a 'victim-blaming' platitude. Negativity breeds negativity. I was put down by my parents an awful lot, and I grew up talking the same way to people, little negative comments, negative bonding, etc. I didn't even notice I was doing it; it was all I'd known and without some kind of insight from outside of that environment I wouldn't have reason to question it. In the end a girlfriend made things very clear for me: a figurative but very real slap in the face, but I'm eternally grateful for it. This is all well in the past. I recognise the patterns of negativity and I do my best to avoid them.
Of course, in my case it wasn't about beating up a partner or demeaning her, but the principle is the same. If you break down other people and leave them with low self-esteem, particularly during their formative years, then they will behave the same. Other stress factors may, of course, contribute (not being happy in a relationship but not feeling like you deserve anything else, not being happy in one's job, money worries, etc.).