It is not an absolute that we use unlimited touches, sometimes use 3 touch. Have a couple of games we use when we do not have enough keepers. 

Unlimited touches in more competitive games 

3 touch in a lot of training inter club games

also depends on the number of players and ability taking part in the session

Oxfordshire WF League play 3 touch in both Over-50s and Over-60s sections.

Charlbury Town adopted same rule for two reasons - firstly so as we are prepared for league matches but secondly as we feel it is more inclusive for players of varying skill levels 

We have sessions for 3 touch and unlimited touch, I think it's important to give people the option to play both and let them decide what they enjoy the most.