The only time I see remote control affect sound quality is when manufactures use those crappy integrated circuit volume controls, like the ones used in Audio Research, or early Sonic Frontiers, to name a couple.
What's the point of building a beautiful tube circuit only to have it ruined by a 10 cent IC.
Cost to have remote control can get quite expensive. A motorized stepped attenuator can get up to $1000 for small lot production.
Cost in my preamps with an motorized Alps control is about $250.00, but a motorized Khozmo can be much more, and they take up a lot of room. Then there are the relay types. Relays aren't cheap, and there are a lot of extra parts involved.
None of these types will affect the sound quality in a negative fashion.