The option for reuse applies to both parties. Someone has to license use from the copyright holder with or without a transfer. In the case of software, the transfer is just an additional complication, by which I mean that the copyright to a Rails app is complicated by the license stack of Rails and the backend and other pieces. There's lots of pieces that the programmer doesn't hold copyright and therefore cannot assign it.

Indeed, but that sentence applies equally to either side of the contract!

Which is why I wonder what the "accepted standard" & "cost of giving up IP" is. I assume it varies greatly across domains -- OP's is "web development".