It's a good idea, but it will tie up space for the charging points (and make sure ICE drivers don't just park there anyway) and have to deal with the cabling.

I think the reason business don't do this is purely for lack of space and ferocity of local planning laws, particularly in Europe.

What I don't understand is why parking garages just don't put a standard outlet there for a trickle charge, as you say, and include it in the cost of parking.

Perhaps as soon as they realise they can charge a 'premium' on the already high parking fees it'll be a no brainer!