Because what you said has nothing to do with having value as a person. A man wanting sex isnt a compliment because it says nothing about a person. Men don't ascribe value to sex- it's a physical act to get off. They physically desire it, and yes that has meaning for them but it and of itself it is not meaningful, especially if they intend on leaving the woman after. A more relevant comparison would be women using men for their money.
Sex is higher on most men's priority list than being valued as a person. Sex actually demonstrates value for guys. No man has ever said "I can tell by the fact that she isn't fukking me that she really values me." Sex is the ultimate sign of "she's into me" for a guy. The spending time and bonding and gestures are that for women. And women still value sex themselves. If a chick is really feeling and valuing a dude she is gonna fukk him. And if that same dude is not making any sexual advances she's not gonna say "Aww look at him...he values me as a person." No she is gonna wonder the what the fukk is wrong with him and assume he's either not into her or not into women altogether. BTW I was referencing guys in general, not smash and dash dudes. A compliment is all about what a person ascribes meaning and value to. And that was my point. The genders value different things so it's silly for either side to project their own values on to the other. The lack of understanding or acknowledgement of these differences is the source of most of the acrimony between the sexes.