Honestly, it probably comes down to taxes. Many Americans are rabidly opposed to any proposal that will increase their taxes by any amount, regardless of the reason, and a lot of school district funding is based on local property taxes. Coincidentally, home- and business-owners who would have to pay that increased property tax are able to have an outsized influence on local politics. No politician is going to raise that proposal for funding foreign language classes.

As sad as it is, learning to speak another language just isn’t seen as that important by many. They don’t need to use anything other than English in their daily lives, and many citizens don’t even have a passport, much less travel abroad.

In addition, aside from Spanish, many areas just lack the resources you would need to be able to develop your language skills from “I get good grades in my highschool German class” to “I can actually use the language in normal interactions with native speakers.”

Think of your local bookstore and libraries. How many if them have a section of books you can just browse in a language other than English or Spanish? For anything beyond Spanish, how often do you see or hear another foreign language? Would you be confident you could find enough conversation partners to use that language even semi-frequently?

Yes, the internet opens up a lot of doors in terms of resources, but you need to be personally invested in learning the language to make them work. Unless there’s a community with great reading lists at various levels for your target language, just searching and browsing bookstore websites aimed at native speakers is kind of tough for being able to just browse and find something that catches your eye and seems on your level, especially compared to just browsing the shelves in a brick and mortar shop. Also, those books are generally much more expensive than English books, for obvious reasons.

Yes, I would be hyped to learn my local school district was going to start teaching the kids 4 languages from elementary through high school, but it’s just going to be wasted money if you don’t have the auxiliary elements outside the classroom in place, or a plan to at least put them in place while rolling out these classes. Otherwise, you’re just going to get a bunch of yokels coming out of the woodwork to say “My boy don’t need to speak nothing but 'American!” And complaining because little Billy ordered 4 books off Amazon.de and it ran them 120€, only to show up and have Billy realize these books are way harder than he thought they would be and he actually needs to order more books with simpler language to get started.

Yes, little Billy could pirate the shit out of the books and stuff he needs and find a discord chat or forum to get in free practice with speaking and writing, but not all students will be motivated enough and tech savvy enough for us to assume this will be a viable method to get results in general.