First off i've played both deacently much and here is MY opinions why TF2 is so much better.
1. Balancing, TF2 is really really balanced. MW2 Noobtubes, G18 need i say more?
2. Teamplay, TF2 is extremely team based. MW2 Ofc there is teamplay but it's really just a scratch compared to TF2.
3. Skill, TF2 if you're a better player you will almost always win over the less experienced played except for random crits. MW2 there is skill absolutley but as before Noobtubes, G18.
4. Gamemodes, TF2 has about 5 gamemodes or so, so it's up to the maps to back them up. MW2 has WAY more gamemodes than TF2 but WAY WAY WAY less maps than TF2 and i really don't think that gamemodes weigh more than maps, balancing, teamplay, and skillfull players get rewarded.
There was MY opinions.