Ya, it simply comes down to the laptop. It isn't equipped to handle games.
You have a few options:
A) Buy a gaming laptop
B) Build a desktop. Even a cheap(er) desktop with decent specs will handle TF2, etc.
C) Don't play.
If money is an issue, than check ebay, etc. There are always awesome deals on there sometimes, and check forums. Our F/S thread here always has some great deals going on used hardware from members.