If a company is offering unlimited anything, then people will use that unlimited whatever. It's not them being abusive. Those people are using what they paid for. Nothing more, nothing less.
For example, if I sign up for "unlimited cloud storage", I take it to mean, backing up all my personal stuff, no matter how large it grows. If I have the world's largest collection of digitized rocks in 8K Raw and it takes up 2 million terabytes...well I think I'm being disingenous by using the unlimited storage.
Or for example, if a friend says "use my car any time you want"...will you really just steal his car and ship it to another country?
I mean...nothing in this world is unlimited for real. And I think it makes sense to say unlimited to mean: you can use as much as you like, but be nice.
Maybe don't call it unlimited storage then :D
If you're a fast runner you can...