There's always been quite a bit of a debate in some circles regarding the importance of historic routes. There are always critics. Some people are saying that the whole idea of historic routes is essentially just marketing ploys.
The whole idea behind this is, of course, to elevate the social and cultural value of a specific highway route so people could somehow someway make money off of it. Maybe they can make money in terms of songs, and popular culture or they could make money through movies that the most cynical version of this criticism is that historical route designations are simply money grabs for Congress people to allocate funding for their districts.
It's easy to understand where the criticism is coming from because the United States' Congress is quite notorious for wasteful spending. There are also sorts of ridiculous budget allocations for dubious research.
For example, it's not unusual for Congress people to ask for grants inserted in the annual budget allocating hundreds of thousands of dollars, if not, millions of bucks to research the sex life of a wide range of animals.
There are also budget provisions for hotels located outside in the United States that the US may not have a direct strategic interest in. It is no surprise that there's always been a historical skepticism for anything Congress does. This is part of living in a vibrant democracy.
Democracy in the United States is particularly mature because people do not look at personalities per se. They don't look at elections as a popularity contest. Instead, they focus on ideology and one key manifestation of this of course is the wisdom of certain budget allocations.
If you look at the philosophical principles behind this criticism, it really all boils down to the fact that the government has to tax out of necessity. In other words, as much as possible, the government should not tax and in the event that it does, it better be careful with the money that people work so hard to produce.
This is always been the American ethos when it comes to taxes because for the longest time, America was a low tax country. Collecting taxes were like trying to pry dollar coins out of a dead man's hand. That's how resistant people were to taxation.
That has changed in recent decades. But there's still a lingering attitude that if the government is going to raise money, it better make wise use of that money, which brings us back to the whole idea of historic routes. How important are they? Is there any sort of larger public policy interested are being served by the proliferation of such routes or such designations.
People have pretty much argued about this all day every day and still not come up with a definitive answer. The bottom line is, they are important precisely because they get rewarded. That's probably not the answer you're looking for but it's the absolute truth.
If people would stop talking about it and most importantly, if government institutions, regardless of the scale and origin, would stop funding it, it would not be an issue. It would cease to be a thing.