I tend to ignore people who are ignorant myself but the way to know for sure that someone is full of shit is to hear them talk about an entire breed of dogs as a whole with a label. There is no doubt that there are EM's just like what he describe and at the rate that the BYB community is growing there will be plenty more to come (sadly) but, like all breeds, there are the Fantastic, the good, the poor and the horrible. I don't believe for a minute that ALL EM'd are like this and I never did but I just happen to own one that WILL protect (Without a doubt) without blinking and is a true guardian so they do exsist. Also, "working" ability depends on what you are hoping to work them at.
I find that the less people actually know, the more they try to appear to know. I would think that in order to have a true educated guess you would have to have some fairly extensive knowledge and hands on working with the breed and I think it is probably safe to assume, he does not considering his comments.
I say consider the source.