While not all men fit the bill, most seem to, and wives/partners just seem unable to understand. Gay men understand better, and it less of a problem in their relationships.
Women just do not understand how forceful the male sex drive is. Just a hint of interest from an attractive female and it can turn them into a non fucntioning person for the day. Their minds will be obsessed. They will imagine all sorts of things.
Blokes can have sex so easily when they are turned on, ah, they can do it even when they are not turned on. They are animals. I don't know a lot about women's sexuality, but for most it does not seem to work like that. They like love and passion. Blokes like this too, but it is not essential.
Blokes can have quick hard and fast sex, or long slow and passionate sex, but it is that, just sex. Absolutely nothing to do with love. They can also have sex with someone they love and if it is any of the above, that is extra good for them.
Do any couples who have been together for a long time really agree that sex is better with their partner than it was when they were young? It could be more relaxed, more agreeable. You know what each other likes or does not (hopefully).
But can anything beat the hot passion of newness? Call me an immoral slut if you like, but I don't think I am wrong.