Sounds like the problem is with the players. If your base is undefended then form a fighter sweep mission with the other players on your team. Fun fun.
Fighter sweep with whom & to where when there's only 8-15 players on each team total.
The mantra "it's the players" doesn't help. You can't change the behaviour of people
as a group by appeal. "Everyone should just..." generally does not not work, as we are individuals.
That's where rules, mechanisms and gameplay design comes into play.