I'll admit, I very, VERY rarely have ever orgasmed from PIV sex. But I looooove how it feels. And I also love doggy-style (something about the depth, the angles, wow). Granted, when I'm having sex with myself, I usually skip penetration altogether, or (only rarely) I'll just "park" a toy with some pressure against a very particular spot while I'm using a clit vibrator.... but penetration all by itself usually doesn't interest me if I'm alone.

By contrast, I can orgasm dozens of times with a clit vibrator by myself. That's great, and I'd be happy to orgasm more during partnered activity too.

Still, all the same: nothing — nothing, for me — replaces the pleasure of having an actual partner in the bed with me, moving inside of my body. And if a partner wanted nothing to do with my vagina, I'd be very disappointed. I haven't had a partner yet who has needed Viagra, but if any of my partners ever does, I'll be very thankful that it exists.