An interesting philosophy but, with all due respect to your Grand Pop, I disagree. There's tons more to a relationship than just sex. You have to be able to rely on and trust your partner. They have to have your back. In fact, the most important characteristic in a partner is sanity. Without that, everything else falls apart..
The problem with marrying a whore, or even a slut, is that they're probably lacking in trustworthiness and sanity. While the sex will be great (sometimes), you will never be sure you're the only one getting it. In fact, as time goes on, chances increase that she's cucking you. You'll know what I mean the first time you're wondering WTF she is at midnight. And I'm sure that will cause your pipes to back up and your mind to cloud like few things can. I've seen this in action on both sides. I've dated sluts and AMP girls; its only fun, but only for a while. On the flip side, I've also seen how they treat their supposed SOs while they were doing me on the side. Again, its a fun romp in the short term, but you'd have to be crazy delusional to marry one and think it's the ticket to happiness. Maybe in ~5% of the cases it is, but those are not betting odds. The better way to go is marry a sane, pretty woman who you can trust and [discretely] step out on her if you're not getting satisfied.
The last thing to consider is menopause. It effects them all, even the whores and sluts. When it comes to menopause, every woman is a ticking time bomb.