Oh no, I agree. It's very tricky to justify concern for the footballers we watch on the pitch in any sense regarding their employment.
A middle of the top flight professional footballer earns what I'll make in the next several years in a handful of months. And what is considered "waged work" for them pushes the usual boundaries of the idea.
If they suffer a career-ending injury, then the disappointment of thwarted sporting aspiration aside, in effect they get to retire early as investors with an established network and special access to opportunities of certain kinds.
End of the day if something like this clause comes in across Europe it'll just be another recalibration of some of the financial parameters of the sport. Footballers will still be paid and clubs will still employ them. Bosman didn't change everything, Webster didn't change everything, and this wouldn't either.
This Belgian ruling sounds pretty similar to Webster to me, but I don't understand the details.