Unsurprisingly, trying to make your body think it's already pregnant via external hormones can have some significant side effects. I mean, I suppose decreased libido probably contributes to the effectiveness of a birth control method, but why bother? Or how about some frustrating weight gain from your body trying to nurture and protect a non-existent baby? Or maybe you prefer that sex become uncomfortable or painful? Even IUDs are only recommended if you're not thinking about ever having kids; the danger of infertility is still too high.
"I don't want to wear condoms" is all-too-often the only reason that hormonal birth control is ever considered. It's my personal opinion that men are the ones that need to suck it up. Every time.
Chances sex is less pleasurable for men? Probably 100%. But the chances that hormonal birth control will significantly diminish some woman's quality of life are statistically significant. The only way to avoid it is to go with condoms.
Don't want kids? Don't want to take chances? Don't have sex. You think it's a coincidence that one of the most pleasurable experiences possible also happens to lead to the continuation of our species? Ha.