Commercial Blue Crabbing

The only "approved pots" are the kind that allow the crabs can come and go as they please (e.g. box traps with doors that fall down and and stay open when they're lying on the sea floor).

And if you left those traps unattended (against CT rules), when the crabs are done with the free buffet you've left out for them, they'll move along to your next trap, and so on, until your all your bait (and the crab) is long gone. Chesapeake-style traps are illegal in CT - these are the ones the commercial guys use down there, and the crabs cannot easily escape.

It's not really clear why they sell a commercial license in CT, but if I had to guess it's just for guys doing other types of commercial fishing. Let's them keep their commercial license bi-catch - meaning they're going for something else (e.g. lobster), but pull up some blue crab here and there. This way they can also sell the blue crabs. Just a guess, and perhaps not a good one seeing as lobsters and blue crabs don't really like the same conditions.

Even if CT allowed commercial-style traps AND for you to leave them unattended, you'd still need to find an area with enough volume to support your little venture. I'm unaware of such an area, but would love to hear about it.