Is your lawyer an in-house general counsel? Probably no. Do you require this person's services for ~40/hrs per week, every week for years on end? Probably no.

I would certainly pay an amazing engineer $600/hr if I could call on them at any time and get billed at increments of 6 minutes, but that would be an insane way to build software (I know lawyers who think its an insane way to do law, but it is the system).