> Without feedback you don't know that the bug was fixed in reaction to your bug report.
In this particular case, they did say they will consider a reward for a severe bug (it was severe, DNS hijack) and then once I shared details, the next day I checked, they had fixed it and never wrote back.
> Is this for reporting bugs outside of the bug bounty platforms?
Nah, in this case they simply had no official bug bounty program/platform.
I would guess that a big factor is mindset and tech culture across different companies or having a bad head of something who doesn't get the point of bug bounty / promoting responsible disclosure.
In this particular case, they did say they will consider a reward for a severe bug (it was severe, DNS hijack) and then once I shared details, the next day I checked, they had fixed it and never wrote back.