Why are Uncharted 2 servers still up while others are down?

I've noticed that the Uncharted 2 MP servers are still up 6 years later, with only like 2500 daily players. I can't help but wonder why these servers are still maintained while games from around the same time period (Resistance 1-2, MAG, Motorstorm Pacific Rift) and even newer games (Socom 4, Resistance 3, Motorstorm Apocalypse) are not available online still. Does anyone know why only the Naughty Dog love? Surely more than a couple thousand people would still be playing Resistance 3 nowadays. I couldn't find any articles online saying WHY they are down, only ones reporting that they are.

I think money is the reason they cut support for those games you mentioned. I`m guessing some of those games weren`t profitable to maintain, i could be wrong. But it wasn`t nice of Sony, or whoever was responsible, to cut off online support for Resistance 3, the game wasn`t that old when they did it so some loyal fans must have been really disappointed by that act.

And soon after the release of Gran Turismo 6, they cut online support for GT5 as well, was really annoyed by that.

I am one of those disappointed, but of course, you pay to play in MS so certain franchises like their own franchises ( Gears and Halo ) have working servers even though games like GOW1 is older than dirt, in the case of Sony, well, you play for free.

Then since people are paying to play online on PS4, we won`t see cases like Resistance 3 anymore, at least they shouldn`t do it THAT soon to various games anymore, in theory at least. But i don`t really know how this all works, i also don`t understand how games like COD 4 can still be active in such "hackfest" state.

The real question is, why is the Uncharted 2 network still up and running?