Most high schools and college age guys that I've known thought about little besides that. If (straight) males were as faithful and monogamous as you claim, why haven't all porn magazines/sites and strip clubs gone out of business? Why is a casual "hook up" culture the norm among youth? Are they just pretending to be homosexuals?
Do you know a significant percentage of heterosexual men who WANT anonymous sex?
I do not. They may want sex, but the vast majority want it with someone they know. I’ve never heard of heterosexual men having sex thru a hole in the wall - unlike homosexual men.
There is a reason why most men have not had 500-1000 sex partners, and it isn’t because women are too picky.