I think the system is fine the way it is. If you want to go for a platinum trophy in a game with a dead online community, chances are the game isn't really all that good, and you are one in million. Just go for another platinum trophy, and have better luck with picking what platinum you want next time.
And I still don't understand anyone who would go for a platinum trophy just to get a platinum trophy. If you like a game enough, you will ask around on the internet to try and get some matches going.







