It's a legitimate strategy, multiple games have this. Going back to spawn in TF2 lets you regain all your health and ammo instantly. There's nothing stopping you from going back to your own spawn for safety. And they aren't out on the field collecting Wumpa by being in spawn, so it's not exactly helping them win either.
They're just trying to stay alive. Focus your attention on helping your team and not chasing down a singular player.
#Can the Spawn Points be blocked for Re-Entry?
cloud geyser
cloud geyser
That's literally how team spawns are supposed to function in video games.
Blocking off the spawn wouldn't help anyways. If someone's power meter is full with a wumpa stash ready for use, they could just KO themselves and then use wumpa stash when they respawn. All safe and cozy behind the spawn walls.