Because there’s no possible way that the government could buy up the 77 stations thst broadcast the NPWS stations.
We’re already subsidizing them heavily because the backup systems to keep them on are expensive.
Edit to add: the demand for AM is going away. Content is cheaper to produce and distribute online.
In stead of passing legislation to bail out a dying industry (what this bill is really about,) they should be looking at ways of resolving the problem.
An easy first step is to buy or otherwise nationalize the 77 critical stations. We can then either maintain them as vital infrastructure or replace them with newer and more capable/effective technologies.
All this bill is going to do is prolong the problem.