You mostly right, but there are some moments that can differ.
First of them is the reputation of the company. If the company is about scam - even the best of us can get negative trust and disapproval from other members. That`s why it is important(for me at least) to find a company with good repatation.
The point you are stating (while its true) is different from what Betwrong mentioned.
You are correct that we might get negative trust if we promote a campaign whose owners are fraud and it makes sense because it will encourage more scam and as a candidate we should be aware of what we are promoting.
But at the same time the signature campaigns never mention that we should only speak good about the products we are promoting.
This eliminates biased judgements which was the point at the first place.
It`s true, that we can right both good and bad things about companies we promote, but the same time i think that is bad idea to wear scam signature even if you are talking that this is scam.
Second - when i found out bitcointalk - i thought that "hero" or "legendary" members wearing signatures of the projects they believe. In this way we are responsible to newbies that believe in signatures.
That's an honest mistake
When I was a newbie I though it's just normal ads that get popped up on any website.
Little did I know they are signatures willingly worn by the users.
And due this mistake we have a problem that i pointed in the first step: if a newbie see a hero member in the thread, and this member don`t telling
in this thread that the company is scam - the newbie can believe in company.