Because electromagnetic waves are...
...massively affected by location/building structures/nearby transmitters/electrical systems/etc. You get the drift, hopefully. What this implies is, one so called, extremely positively reviewed radio might work just that way in one persons dwelling, but in another, isn't worth the $$.
Combine that with the fact that significant demand for the old trusty clock radio ended a couple decades ago. And if one $20 doesnt' work, one can simply find another since they are comparably inexpensive vs other types of (arguably) 'smarter' devices.
Hope you can find one you like though.