[scrubbed]

Just to clear things up until Xhin can make a better reply:

There was a password dump several years ago due to a specific exploit that has since been patched. HTTPS wouldn't have prevented that attack.

The primary purpose of HTTPS is to encrypt all communication between your browser and the website (Gtx0) so that someone 'in between' can't just view your password or other data in plain text as it's transferred. Useful if you're logging in to Gtx0 from a public wifi connection where someone else might be snooping traffic.

The best advice I can give is to use a different password for Gtx0 than you use for other services. Which you should be doing anyway, given that re-using the same password makes you vulnerable regardless of HTTPS.