If you see so like me, then camping is staying in base with no acceptable reasons. Mostly, aliens camp, not humans.
ATCS is basic example how aliens usually camp. They get big, stay just outside of human base and wait until unarmed humans pass by. If not, they yell "camp camp". Aliens got advantage here and aliens should try to destroy some buildings, not humans.
There are plenty of reasons to stay a while in base.
1.Base is heavily attacked, humasn MUST defend or they loose.
2.Some important building is missing or smoking. It can be some things, No arm/medi/tele, smoking react/tele, no turrets etc.
3.Waiting for a teammate to go out. Solo a tyr is possible, but 5 out of 6 times you fail on it. Having a teammate with armor and weapon helps a lot.
4.Base movement. Its nice to have someone to kill those dretches.
5.Cant get out of base. Behind every corner, its a big alien. Humans are forced to defend. They rush corner, and rest in base, repeat.
6.After a failed rush while you and your fully armed teammates are killed by bunch of dretches, its wise to stay a while near base, to defend possible counter-attack from those feeded aliens.
7.Protecting a important structure on SD. If you cant build arm/medi/tele, then its wise to have someone in allways defending position. Loosing it ends game, so its worth alot.
Some things are encouraged.
1. Usually its not acceptable to stay in base to earn cash. Shooting bullets is normally way faster earnig method. If you got othing, stay behind a teammate.
2. Usually its not acceptable to stay in base to drain evos from opposite team. I mean, if you are s1 and you know there is only 1 goon, staying in base until there are only dretches left is not a good style of play. Same thing is for tyrants.
3. Usually its not acceptable to stay in base to get stage advances. Earn frags, do not wait them to come to you.