It's sad that 95% of people's exposure to HD radio is through either a table radio or a car stereo; not real hifi stereo systems by a long shot.
Typical table radio characteristics:
-only one-way speakers, no crossovers or tweeters, that is, just a single "full range" cone, totally unheard of in better loudspeaker designs that at least have tweeters if not also dedicated midranges w/ crossovers.
-stereo separation between L and R speakers usually around 11 inches
, not feet, if you can even call
-built-in amps having maybe a few watts of power at best. Puh-leez.
Typical car stereo characteristics:
-listening position is asymmetrically placed between the two speakers making sound-stage localization dubious at best (what audiophiles like to call "imaging")
-extremely noisy environment due to engine noise and road/wind noise makes the better noise floor of HD radio impossible to detect unless you park and turn the ignition off
-maybe component speakers with tweeters and woofers in some systems but most with nothing more than a whizzer cone glued to the cardboard/pressed paper woofer for "the high end" in the vibrating stamped metal car door "cabinet".
The only type of sound reproduction systems lower in quality to these is perhaps the "clock radio" [although defining where table radio ends and clock radio begins might be vague] or perhaps a pocket "transistor" radio.
Add to this insult the fact that most people have a hard time distinguishing what aspects of the sound they hear is from the particular recording or the arbitrary compression setting the transmitting radio station has chosen and it's no wonder many think "It's no better".