I think the miles are dependant on program, and status. If you have no status, they're harder to use, no doubt.

But with Aeroplan for instance, one stopover is free. Have you ever looked at the price of YVR-BOS-BUF-YVR? It's insane. Or YVR-PIT-YYZ-YVR. Or YVR-SCL-MDE-YVR. I've booked those on points because the stopover only costs me whatever that airport fees/taxes are. I've managed to go to multiple canucks road games on 2 game trips because of this feature. Those trips on paid tickets would be otherwise prohibitively expensive. The other option would be to fly YVR-BOS one way, figure out a way to BUF, then buy BUF-YVR on the way home. Been there, tried that, SOMETIMES it works out using a few diff airlines, but often it doesn't.

So sure, using the miles on an F trip you otherwise wouldn't pay for is great. But for me, even once my status dries up, using them even for just pricey Y trips is great, especially because I won't blow all my miles in 1 shot.