Certain things get a lot more complicated when you go from AC to DC. Two of the most significant issues for home use are connects that can be disconnected under load (arcing is a serious issue here) and turning DC power on/off with mechanical switches (arcing is also the issue here).

Industrial DC devices get around these issues with stricter rules and bulkier/more complex devices. E.g. electric cars use contactors to connect batteries rather than a simpler relay/switch.