If I didn't have a PS4 yet, I would have bought one for Uncharted 4. Yes, it would be worth it for me for the grand experience and the 100s hours of I'll play between replaying single player and playing MP.
Those who think it's stupid to buy a console for one game are actually the ones being stupid. Obviously, the one exception is someone buying a game they know absolutely nothing about, but just assume that they will enjoy it from the impressions of other people.
If a person is buying a console for series they enjoy and offers hundreds of hours of playtime, how the fuck is it stupid to buy a console just for one game? What difference does make if they are buying it for one game or splitting it between many other games? What if it's just more fun to a person to continue playing that one game? There was a thread last year on GAF where people shared their highest play times and there were people who have put 200+ hours into Demon Souls and other RPGs. Also, isn't there other features from that the console that could be useful to a person like the spotify/netflix app, blu ray capabilities, or being able to follow streams?
I bought a Wii just to play Smash Bros and it definitely worth it! It wasn't the only game I played, but it was the one game that pushed me over to buy it because I love the gameplay, it's probably a top 5 local multiplayer game still, and it's I've been a fan of the series.