Many manufacturers do "get it" and do things the right way but production builders are forced by the market they sell into to make cost/quality/price calculations and the resulting "compromises"..
Below is an example of one builder in Maine who uses nothing but tinned UL1423 marine wire and FTZ factory made adhesive lined polyolefin heat shrink connectors. Just this ONE bus of neg crimp connectors probably cost as much as all the cheap connectors used in a typical 40' production boat...
You CAN buy quality but as has been pointed out you'll pay for it and this level of electrical work is not going to happen at the low end of production boat pricing...