While I cannot agree with deleting this site, which would be quite a sad thing for me, I agree that the website can be improved a lot regarding this. I am planning to make the website to download more gradually than downloading the whole video first, which will let you escape from the site without downloading that much!
Google's homepage is 2.3mb right now. This page loads 16.2mb, so about as heavy as loading Google 7x.
For comparison, Youtube's homepage is 14.2mb for me.
So really it is not that much.
That's a good rule for products, but this is HN. As a reader, half-baked projects are super welcome.