I know "unlimited" options are abused, but Dropbox isn't unlimited?
I would agree if we talked about Backblaze with "unlimited" backup for next-to-nothing, but this is Dropbox which is rather pricey and also limited to a very specific number of (Tera)Bytes.
If they cannot deliver on their promises, shame on them.
And backend is always S3+Glacier which costs about $25/TB/month for storage and $100/TB for download, so not just that filling up your quota to the brim costs them more than twice as much as the what Dropbox charge for a 2TB quota, but overwriting and retrieving the files is going to seriously hurt their budget. Not your budget, none of your business, but that's how it works, that's why anyone other than them went bankrupt, and that's why they don't try to be nice to advanced users.
Edit: But most importantly: if you sell me "x units of anything" it is not abuse if anyone use whatever they thought they bought.
I'll discuss it if a highly technical user keeps "trashing" it by uploading frequently changed and unique data for no good reason (like in trashing a cache) etc, but ordinary users, filling their quota to max? No way.
Gloriously boring, no flashy corporate identity. I give them money and the give me file storage/sync. One or two bugs and questionable UI choices, but it just works and I don't see them doing a pointless chain of redesigns or ads.
I'm tired of constantly having to re-learn where the upsell buttons will appear, so that I can avoid them when I actually use the product that I paid for.