Cooler - to answer your question - its bit complicated because its based on individual their desires/emotions attached for example
most male aren't ready to get into a serious relationship, so they stick off having friends with benefits and most of the time they don't really tell the girls direct because most highly the girls develop the feelings faster and they'd get pissed off and feel like that they're beign take advanagte of.
and as for the casual daters - you know there's some people do date around, and have sex with others to find out if they're really expertise in the bed, or feeling attached you know? (they dont really consider it as friends w/ benefits) they consider it as the 'casual daters'
as for hedonist - most students at the college, and are away from their close ones, and most of them time they feel lonely, and wanted to be with someone, and they often misunderstood it as in "relationship/dating" really not - they're actually doing the 'friends with benefits'
i think its safe for college student to have friends with benefit, cuz the students comes from other states and go to college for education, not for the relationship - they can decide relationship after they graduate, i suppose.
as for the "nonromantic/realist" i know there's certain individuals who believe that there is only one true love, and it only happens once, and of course - they do not believe in friends with benefits - they can continue on dreaming to meet the true love.
everyone comes with flaws, no one is perfect. its up to individual if they're willing to accept their others flaws, and build the relationship, then its good.
often people get married, and don't really know each others flaws which lead to divorce.
(i dump guy who complain i bite him)

i told him go and find a barbie, continue being plastic. haha
friends with benefits often lead jealously, when one person start develop more feelings, and which isn't healthy
i was told there's many bisexual people who do not feel jealously, they often get involved with friends with benefits for experiments purpose to find out their true identity .
people are still racist nowdays.. sometimes the family wouldn't accept her white daughter dating with black person - so that leads into friends with benefit.
high class / age - for some guys who's so desperate to be fucked, so they'd go out with the whore, just to be satisfied. he wouldn't commit anything to the whore, so this lead to 'friends with benefit' as well.
same thing comes with money issues - for women/guys who want to get laid, and its difficult to find a love one due to their high requirements/picky situation, so they'd degrade themselves to do the friends with benefits with people who are low income, single milfs, n etc.
so i think i vent my opinion too much, ha.