Free rolls are not something that someone can get rich on, but there is always a chance to win $200 or some other slightly bigger winnings than those initial 7 satoshis (more or less depending on the BTC price). For some, even that $1.44 per hour would be a very good salary, because in some countries people work a whole month for less than $10.
As you say, you collect a few more things in each free roll, and each 1 reward point can be exchanged for 1 satoshi when you collect 100 000 of them.
I agree but the chance that you win 200$ is very very slim. It doesn't take much time to do the freerolls and lets not forget that what today is maybe worth 0.002$ can become 0.02$ or even higher. If you only collect RP for free rolls, it will take years before you reach the 100,000 RP mark but it is a nice extra.