Too many servers have 1.8 SG, some on par in terms of difficulty and items. 1.8 is an outdated version and sooner or later, people will drop that version.
We know 1.8 (not counting 1.8.9 last year) is 2 years old. What if Cube stayed like that for the next few years and the latest MC by then will be around 1.12+? It's like saying if one wanted to still play beta MC now when the full release was released years ago. I'll ask you this: would you still want to play on a 6 year old version years from now?