I chalk this up to pure laziness. Envato, as much as I feel they are a bad company who should go out of business makes one thing clear, download your files whilst they are available. I too have lost a number of files due to a hard drive crash. Every time an item is updated, I download it even though I might not be using it.

Being old school about archiving your data is still the safest, most foolproof way of ensuring you are not reliant on a company to backup your files.