Anyone signing up for a bonus definitely needs to read T&C with that bonus. That said, the biggest issue I have with them (outside of being limited to under $5 even on the Super Bowl) is this policy does nothing but give them the complete opportunity to freeroll anyone they please. They "booked" the bets (I use that term loosely) and clearly would have been happy to grade those a loser with no issues. Someone gets hot and didn't read the T&C, freeroll time if the amount is significant enough.
On the flipside, I understand why they have the rule in place. Allowing full deposit+bonus bets leaves way too many opportunities for bonus abusers to take advantage of them. I am sure they must have got hammered at some point, esp when they offer 100% bonuses (and I think reups are fairly generous as well?). If they were a bit more like a BM or BO shop, they would at least make that key rule very apparent even upon accepting a bonus (i.e. checkbox I agree with these terms and that one spelled out).