May I just point out that "Unlimited" isn't going to be Unlimited, as no one gives unlimited, but you have a high amount of space maybe? (Please correct as I am most likely wrong)
As long as the usage is legit, it's as close to unlimited as you can get with a few restrictions in place:
(1) There is an absolute upper limit of 50,000 inodes (basically files or folders; everything's a file in a Unix-type environment) for Free Hosting accounts.
(2) Individual files cannot exceed 10MB; anything larger will be auto-deleted some time after four hours after their creation time. That's enough time to upload and extract a large ZIP, or to create a downloadable archive, without taking up any permanent space on the server.
(3) The Free Hosting space is provided for web site hosting, so a "site" that is primarily a front end for downloadable non-web files falls outside of the Terms of Service. Similarly, the email accounts are there to provide basic functionality; they're not intended to allow you to "archive all the things!"
At first glance, that might sound like a 500GB cap that you can never quite reach, since there's little chance that all of your files (in a "flat" site) are going to be almost exactly 10MB in size. A more reasonable average file size is probably closer to 50KB (between tiny text files and bigger image files), which would work out to about 2.5GB for a static site. But keep in mind that you can store an awful lot in a database without using any additional inodes. A database-driven text-heavy site can get to be quite large before the nice folks here will have a little chat with you about your usage and why you might want to upgrade to a paid hosting plan.
The bigger bottleneck is traffic. That is unmetered, but your account is on a crowded server with a lot of other accounts and there are resource limits for processing. If you have a huge site, there's probably a reason for it. You'll likely run out of resources to serve your users before you run out of space for your site.
So no, not "unlimited". But not unreasonable either. And free. I remember when 100MB on a web server was $1500 per month. This is better. (Now, you kids need to get off my lawn.)