In practice, I *do* use the radio, if mainly for background music, and am a bit disturbed that Yamaha, who made my receiver and also an older tuner in a system in another room, seems to have cheaped out with the radio in my receiver also. However, that might not be so bad a thing, except that the old tuner is far more sensitive. Anyway, I've listened to the streaming versions of good local FM stations (NPR affiliates) and, frankly, plain olde FM from a decent antenna sounds better. The streams are shrill, though of course, minus the hiss that's below everything on FM, but the biggest issue is that the streams are compressed, horribly so. Yes, the FM is compressed too, because the program needs to be above the hissy noise floor, but the compressor (on the classical/jazz station) is much better-behaved, less obnoxious about its actions. Why does a stream (or HD, for that matter, being digital) even need a compressor?
Essentially, modern equipment provides a tuner because it's necessary to call itself a receiver. I get the impression that nobody really cares about making the tuner work well any more (much like with the OTA side of TVs). Overall, it's something that can easily be ignored if you don't need it, and there are a lot more receivers out there than "bare" multichannel integrateds.