Hmm. It's possible that you are sexually incompatible, not just in the frequency with which you would like to have sex, but in the type of sex you would like to have.
There is no need for you to actually state which of these sound like you but they are possibilities to consider -
A) You want complicated, time-consuming sex that involves lots of dressing up, toys and fancy scenarios. Some people like this, others do not.
B) You want 'maintenance' sex ie for her to let you hop on and have a go whether she's in the mood or not. Some men like this and most women find it not only distasteful in itself, but it festers away at them that their supposedly loving partner sees them as something he has a right to stick his dick in.
C) You want sex that she finds dull - always missionary position in the marital bed, no talking, no oral... she's the one who actually fancies a bit of dressing up/toys/handcuffs. Again, some people like very straightforward sex and others do not.
A further possibility, if your wife had a religious upbringing (religion is utter poison and does massive damage to sexuality) she might either be unable to rid herself of the idea that sex is a bit disgusting and, once you have children, totally unnecessary - or she might be gay and unable to admit it to herself or anyone else.