major issues if the server was about to run until the Earth explodes:
1. who would pay for hosting?
2. would you expect new features during xy years?
3. some features cannot be implemented without wiping the server
4. one silly overlooked bug can fuck up the whole economy until the season ends
5. one insufficiently checked feature can fuck up the whole economy until the season ends
this game will become boring at one point, trust me, so you, as a player, do want some refreshment... and let me tell you, for some of us, it's more exciting to see the full wipe changelog than if the server was kept alive until we all die. This also gives newbies/newcomers/other players a fair chance to keep on track.
Sometimes, though, the wipe changelog is not what we were looking for.
BTW - this is the third season since 2013 and it's currently running for 1.5 year, so I would say it's pretty stable and long-lasting.