Their fuel policy is perfectly legal.
But they have to know, RYR pilots, how it goes:
"I prefer you to divert from time to time than carry extra fuel every flight"
And the consequence for RYR pilos is that they have to make decisions earlier than "conventional" ones. With RYR fuel policy you can't wait to see who is the first to request diversion. You have to be the first. You have to know that if things get difficult in destination, there will be traffic jam in the alternate, so you have to divert early.
If they don't understand this, then that policy is dangerous.
They must understand it, and answer with this:
"OK, as you wish, I will divert every now and then, no problem"
RYR has the right to use that policy. It is their pilots who don't know how to apply it.