There will always be a war between developers and sales. Sales always needs a foot in the door - and incomplete software can get them there. The customer (and sales team) might even expect faulty software, but just as long as you can demonstrate some features can be delivered that might be enough to get the sales through (and pay for the better quality).

It's great that we want great software and even make the customer be part of some feedback cycle but sometimes you need to play "dirty" to make your company survive, and making your sales department happy is one of them. A good sales department knows the business and requirements better than any developer and sometimes you need to listen to them and not "agile your way around it".

Too many drinks with the VP Sales guy yesterday. :/