Ghosted and black-balled? - Former Interviewee CTDI Employee Review

I interviewed for a role and they made me an offer.. it seemed a little low for my level of experience so all I said was " is that negotiable? " - the guy said "I'll have to check" and they ghosted me. When I checked back a few weeks later he said the job was closed (not filled). That was 6 months ago and the job is still posted. I have a former colleague who used to work for CTDI and when I shared the story with him, he said "Oh yeah - if you don't enthusiastically accept their first offer they black list you.. they assume that you'll never be happy working there." That's pretty strange and extreme but it appears to be true.