[blihp]

The difference is that the front-end code runs on 'your' computer, the back-end code runs on 'their' computer. You typically don't care what point of sale software a store you are doing business with is running on their cash registers or the myriad of software run on the systems of the various manufacturers of the products it sells.[1] However, when you go to their web site(s) and it uses a bunch of minified, obfuscated code that runs on your computer... you should care about that.

The idea behind 'free' software was that you should have access to/control of the software running on your devices, not everyone else's. It was originally a pragmatic solution to a problem, not an abstract ideology that it's morphed into for some.

[1] It's up to the business in question to care about the software running on their computers.