It;s a 5 month old thread. But to expand on what DrawTheLine, Jtfoxlove, anonymous4 have said:
Most women, most of the time do not get sufficient sexual pleasure during intercourse with most men.
However, most of the time, this is more down to the men than the women. IE there's a lot of truth in what's been said so far in this thread. But that truth is largely down to the lack of love making skills in the vast majority of men. It's not down to the practical biology in women. It can sometimes be down to the practical psychology of some women.
All women have nerve clusters in their G spots, deep frontal spots and deep rear spots inside their vaginas, It's then a case of stimulating one or more of these in the right way by the man combined with the right frame of mind from the woman.
There are also angles at which the clitoris may be given some stimulation by the top of the penis or the man's pubic bone during missionary,
A fundamental statistic of sex is that it takes a man something like 5 minutes to reach orgasm - on average - compared to 15 minutes for women. Far far too many men are selfish lovers. Doing what pleases them too much and not doing enough to please their partners.
The sad fact is that it doesn't have to be this way. More men should learn about making love with women. In this day and age with easy Google searching and good information being freely available on the internet. As well as women being relatively liberated now that we're in the 21st Century and not in the 17th Century.
My last 3 girlfriends have all been able to orgasm from missionary with me. Not every time. But often enough. My first 2 girlfriends rarely, if ever, did so because I didn't know enough about the practicalities of sex with women then.