Usually when I ask them they just completely ignore me. After so much asking I usually ask them to go to a build server if they're so obsessed with their ridiculously useless buildings. They refuse.

these people should go to build servers

otherwise kick grief rape ban whatever you want

period

This is a controversial one. Personally I dont think its fair to kick someone for being a noob. You have to give them the benefit of the doubt that they are noobs and not deliberately being malicious. However, if it is quite clear they are simply ignoring the team play as you describe and people are asking them to help instead but they refuse then yeah i dont see why not.
The best way to avoid this is to play on a good server with an admin though really.

Are we allowed to votekick people because they are building stupid useless buildings in main base and not doing anything to aid the team? They should go to a build server, they ruin the game for the people who want to actually, well you know, attack and get the intel, the main point of the game with these maps. Building a tower into the heavens while your frontline gets raped is actually as helpful as someone griefing.