I’ll offer the unheard viewpoint-- a straight male who enjoys prostate stimulation!
To my fellow straight guys: yes, the first time you do it, and probably for a while thereafter, it’s uncomfortable. It feels weird. In first times I had experience with it were in medical settings, and let me tell you (and any gay man reading this), it’s PAINFUL. Shock-out-of-your shoes painful. Nothing homophobic about that, just the truth.
But. . . On my own terms, over time by myself and with some past crazy-as-hell girlfriends, I’ve learned how I feel. What was unpleasant at first eventually became pleasant, and then downright enjoyable.
Now, the doctor’s office is still uncomfortable, but it’s not painful anymore. I guess that once you’re “broken in,” it never really feels painful again.
That said, back to the OP-- in my reading, even the men who find a prostate massage pleasurable don’t always orgasm from it. I, for one, have never had an orgasm from prostate stimulation alone. It’s an intense feeling, an enjoyable feeling, but alone it’s never been enough to get me over the top. Other men have different experiences (YMMV).
One thing to remember is there is a difference between a prostate orgasm and prostate milking. I believe that the latter can be accomplished in virtually all men, i.e. via the prostate you can be stimulated to ejaculation without the accompanying orgasm. I believe you could hear more about it from some BDSM/chastity fetishists (allegedly, it’s quite frustrating-- release without satisfaction, and all that jazz).
Finally, and don’t forget-- part of the issue for men who’ve never had anything inserted in their anus is just that. Forget about whether touching the prostate feels good or hurts-- simply the insertion of a finger into the anus without proper warming-up and lubrication will hurt. Of course, these same men who complain about a finger will then turn around and pass a bowel movement the size of a beer can and think nothing of it, so it’s not the size that’s an issue-- it’s the direction, and the readiness/purpose.
Anyway, my personal mantra is, if it feels good, do it, and stimulation of the anus and prostate feels physically good for a reason (nerve endings galore). It may make one “weird,” but it doesn’t make one gay.