Hardtails are just a different flavour of riding, with normal MTB's my favourite bikes are actually hardtails, and for most local riding the most fun.
I would say you need the skills to pay the bills though to ride one aggressively down any enduroish type terrain.
Main problem with EMTB hardtails is the geometry is more commuter than committed, my E-Sentier is about as aggressive an EMTB hardtails as you can get and the geo is still way off what I would ideally want.
also full suspension EMTBS do a great job of hiding the weight, whereas with a hardtail EMTB you really notice the extra weight IMO, my hardtail is prob 2kg lighter than my FS but feels heavier to ride, though due to the short reach its much easier to wheel/manual for all of the couple of meters I can manage to do! You also feel like you have taken a proper beating after 2 hours riding hard on it.