> Because the days of a service manual and a backyard shed are over
They really aren't, as much as the manufacturers like to tell you they are.
Sure, the sheer amount of sensors/vacuum systems/electronics/etc make it look too complex for the layman, but as long as you've got an OBD scanner and a laptop, you can make quick work of most things. The biggest issue is manufacturers currently having an obsession with inverse torx head bolts in unusual and frustrating places (i.e. pull the top end off the engine using only a 10mm, 14mm and 17mm, and then juuuust at the last step, there's a sudden 6.5mm inverse torx bit needed to be fetched from Narnia.). But you can always get parts.
Electric cars will be just the same - in fact, I think they'll be easier for the home electrician to work on. Most of the modular manufacturer-specific parts can be interchanged for other components (inverters, batteries, etc). It won't look as neat and clean, but considering that electric cars are fundamentally less complex than internal combustion engines I don't think people will struggle.