So far this scheme has worked out fine for the original creators of Ripple-- who've extracted hundreds of million selling their massive premine to an ignorant public, then abandoned the original and did it again. What we're seeing from signal now is just a third generation of the same scheme, preempting the ripple founders from doing it again (or maybe they're involved behind the scenes, who knows?).
So long as there seems to be no consequence except a massive windfall (SEC fines against ICO/premines have tended to be a fraction of 1% of the funds raised), it's unsurprising to see them continue.
The fact that it may kill one of the more useful secure messaging apps as a side effect? Welp. This is why we can't have nice things: Collectively, we're better at funding borderline scams than public goods.