In your statement below, you ignore again the basic profile requirements of a real teacher. As is standard everywhere in the world, a teacher needs to know his subject he is teaching and how to teach it. This is normally achieved by a relevant degree plus additional professional teacher training.

For obvious reasons, this is not always the standard in ESL. ESL is mainly a business run by and consisting of imposters, con-artists and other kind of social misfits that do more harm than any good to their students, Pretend "teachers" with fake degrees and TEFL certs from part of this disgusting scenery, and none of the main players - the provider/owner nor the "teachers" they employ - is giving a damn on the students who pay them. Holding a relevant degree and proof of proper teacher training are therefore criteria of quality assurance to set the decent schools apart from all those shitty operations that don't provide what they promise. Instead of speculating about why people value degrees (those who hold them and those who do not hold them), you should perhaps better look at the original purpose which they serve.

The thing about degree holders is that most of these types who decide to come to China do not have negotiation skills. They most likely grew up in a predominantly win-lose type of household where their ideas/opinions were marginalized and they were beaten down whenever they expressed something inconvenient to the authority within the household they were living in. Usually the only outlet is education, and they cling to those pieces of paper called degrees. There is nothing fundamentally wrong with getting more knowledge to raise your own self-esteem.

On your input below: A degree always involves a major where the degree holder has been certified to be an "expert" in. Outside that area of his major, he is not an expert and not a "know-it-all". But a good and broad spectrum of general education and interests helps to extend an educated opinion beyond the narrow level of one's major and may prevent you from becoming a narrow-minded person focused on his subject area only an to take a more holistic approach instead. Especially in ESL, where all kinds of people mix - the better educated, the less well educated and the uneducated - the less or uneducated will always label you a "know-it-all" when you put them in place because of their unprofessional and unethical attitude and behaviour. Typically, a "know-it-all" is someone with a big mouth and pretends to be always right but lacking the intellectual and professional substance to prove his point. Then, it's more about the ego than the issue you stand for. The less and uneducated in ESL, who compete professionally with the better and well-educated, have nothing than this "know-it-all" label to throw in their favour because.....----- their brain is quite empty in terms other good points they could make in their own favour to justify their own miserable status as pretend "teachers" (= deechers) in ESL. Get rid of them, they serve no purpose other than themselves, they are no good and entirely useless like those who employ them!.

Where the problem comes in is the degree holders will suddenly fancy themselves to be experts on every topic being discussed. They usually think of themselves as the know-it-all in an ESL office amongst other expats.

Agreed on that bit below. Thus, a real educated person would never consider himself to be be a "know-it-all".

One should remember that knowledge is infinite, and to truly possess knowledge is to be humble.

Whether ESL teachers/deechers "lack this humble mind" is a matter of the individual personality involved. Those educated and with a professional profile are less likely to lack it because "education" does not only refer to the level of knowledge and expertise someone has but also to the personality behind.
One important part of the educational process is personality building, growing and maturing. Uneducated con-artists and imposters in ESL are immune to all of this. If you have a bit of practical life experience, you will soon find out when dealing with other players in ESL.

Most ESL Teachers/Deechers lack this humble mind. Tells a lot about the level of character that they have.