It's weird that DLINK's response was basically "tough shit buy our newer product we don't work on those anymore" especially given the extent of the attack.

This calls for new legislation. There are FTC best practice laws being discussed for just this kind of situation.

https://www.ftc.gov/system/files/documents/plain-language/913a_careful_connections.pdf

So, basically the enforcement of the above documents recommendations from what I understand. Not an expert though.

The thinking is this kind of bullshit directly compromises national security.

I agree with that thinking.

Is there a nice up to date list of companies like this that have clearly little desire to improve security or are just very anti consumer?

I'm still learning Cybersec in general, if I'm reading this right, were these credentials hardcoded in by D-Link, these devices reached EOL, and so they refuse to remove that backdoor on the basis that the devices are EOL?

Is there a likely reason that these were left in, like could it have been a development oversight, or does it look more likely that this was malicious?

Regardless, I definitely hold the opinion that D-Link should do the right thing for their customers and patch that vulnerability, regardless of the device being EOL, similar to how Microsoft pushed a security update to Windows XP re WannaCry when it was EOL, on the basis that "Yes, XP is unsupported and you shouldn't use it, but we are patching this particular vulnerability anyway."

Well I’ll add D-Link to my ‘never buy’ list. Not just for their crappy response, but for the poor security practices used in a networked product in the first place!