Correct me if I'm wrong but I watched a video once where porn stars who do both regular sex and anal say that when a guy is big(length and/or width) they prefer to do anal since it can take the monster cock better the the vagina can.
I'm not in that category, I've had many compliments on the size of mine but never refused. I'm not a huge fan of anal but do enjoy it but again not asking for it. "Why jump off a plane with a parachute if the plane can land itself safely". Just saying