Not all, but most use the press togehter receptacles for several reasons. They qualify as a junction box with NFPA, they are quicker on an assembly line and they are less expensive.
Mike, RVIA & RVSA Certified Master RV Technician
Amy, Dr. Assistant - Roxie & Mei Ling, four legs each
2000 Gulf Stream Scenic Cruiser 450 hp & 1330# torque
06 Saturn Vue, 06 Chevy Z71 4x4 & 2014 Corvette Z51 M7