The only maintenance headache IGHs save you from is cleaning the cassette - and jockey wheels should you have a frame that deals with chain tension. But then you just exchange one headache for another.
You still need to maintain the chain, adjust the gears, even periodically open the thing up and deal with its internals.
On paper they sound great, and they are good, but the benefits aren't so clear cut when in the real world, which makes them a hard sell.
Yes, but I can get an entire eight speed indexed drivetrain for a whole lot less, and don't have to worry about chain tension :)