Huh, I never heard of 'stealing with acknowledgement'. That'd be plain usage.

> I’d be inclined to agree with the coworker.

I'd think that co-worker would be subject of constant derision where people would run every trivial thing by them asking if they had thought it originally.

Edit: To be clear I support directly confronting folks taking ideas often without attribution or taking to higher ups if that is so important. But social shaming means the person better be prepared to live up to much higher public standards than it would be for some interpersonal issue.