Who has legal control over the New Vegas exe? Obsidian? Bethesda? Is it one specific individual boss at Obsidian who could order it to fixed, just like that?
That stupid mod limit bug will probably never ever be fixed by whomever it is, and while it's just an inconvenience in light of merging mods, it's still so silly that it was left unpatched.
Bethesda is some kind of lumbering, unthinking monster these days, who the hell knows what's going on with them. But Obsidian? Would they really go insane with rage if someone said, "Please let me fix this bug for you." It seems almost mentally ill for a thinking person to say "No touching it!
NEVER! LEAVE IT BROKEN!" They were supposed to be better than the lumbering giant corporations of pure evil.
And yet, that seems to be the case.

game is too old for anyone with authority to care.

technically, there is no limit. the game just becomes increasingly unstable the more external content it has to load.

Best thing you can do is merge plugins so the game isn't reading off so many. it will be more stable that way, but stability depends on how optimized the mods you're using are.