This is a stupid statement. One male crab can impregnate multiple females.
Better leave that male then. Think of all the virgin females that won't have an opportunity to procreate because we took her fertilizer.
It is legal. But one day the same people keeping females are going to cry about the lack of crabs. People used to keep tons of herring, winter flounder, weakfish etc. Look what has happened to those populations. I don't think you can even keep a herring now. You can keep two winter flounder and only one weakfish.
Everybody should do their part to make sure the crabbing population thrives for future generations. If you catch 52 crabs with two being females, do you really need to keep them. Isn't 50 enough?
Natural Resources has also put catch limits on those species. Same thing they've done with crabs. That's how you manage a resource. You let experts due the research and implement a plan.