Don't see why NTL cannot give this facility. The technology is obviously there as Pace do one for Freeview as well.
http://www.argos.co.uk/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&langId=-1&catalogId=1751&productId=86142&Trail=C$cip=12724 >C$cip=12779&categoryId=12779
Granted you would have to buy one, but thats the same with anything such as a video recorder, dvd player or plasma tv or widescreen tv so if people want it and are willing to pay for it then give it to them.
Smacks of lack of customer focus on the part of NTL, "let's just give em the basics", mentality.