The problem here is that everyone seems to think that digital equals quality. Sometimes it does, sometimes it doesn't.
Ever watch a streaming video over the web? That's digital video but the quality is no where near the quality of anolog cable.
Most cable companies are using digital cable to compress the programming in order to allow more channels, and broadband internet access, on their limited bandwidth. If they increase the quality of each channel then they have to reduce the number of channels offered. Many consumers are choosing between cable and DSS based on cost and the number of channels offered so the cable company has to offer the channels or they'll lose customers.
The DSS providers have the same problem--limited bandwidth--and have manipulated compression to increase the number of channels that they carry. More satelites means more bandwidth and offers the potential for better quality, even more channels, or some of both.
So a digital signal has the potential to have better quality than analog but it's no guarentee. For those using moderately sized sets, more channels probably has more apeal than high quality.