In my experience and as Harry has pointed out (still owe you a beer by the way from Dave's esl cafe yonks ago) trained teachers don't get 'pissy' and it's certainly not a territory thing as when students start working with untrained teachers they can spot it straight away and understandably don't want to part with their hard earned when they feel they are getting taught by a mug (sorry for the generalisation btw, but in my experience this turns out to be true). We get 'pissy' when an untrained teacher tries to tell us how to teach/tell us how easy it is which is understandable - if a newbie teacher comes from the UK/America/wherever and says to me (as they have done):
"this teaching is great, I turn up, chat about stuff for an hour and they pay me 60zł" then on the face of what they've said I would get annoyed because the teacher is clearly not a teacher and some poor Polish sod is wasting his/her money.
Other lines which will get a rise are:
"We don't do grammar, they know it all anyhow"
"There's no need to prep, I just talk about their day" etc etc
The issue here is the typical Polish student.
The typical Polish student is:
hard-working
can see through bullshit / spot a mug
not fantastically rich
ambitious
If the student thinks that you fit the bill as a teacher (s)he sticks with you as Polish students tend to be loyal (and through word of mouth find you other students). If they don't, they don't hang around.
There are qualified teachers who are rubbish an unqualified teachers who are good but the issue that remains for people who come to Poland without a CELTA to teach is that reality suggests:
1) no decent school will allow you to teach their students.
2) hoping to rely on private students is totally misguided as it takes time/contacts in place to give you that network of privates
This is why the message should always be "get your qualifications before you come to Poland - more than likely CELTA - and you won't have problems". Poland has an abundance of qualified native speakers in all major towns as well as better and better Polish natives who, even after 5 years of Philology are paying money to get a CELTA.
What should that last fact highlight to a newbie? A native Pole who spent 5 years learning English to a level of detail of which they never would want to or wish to STILL has to get a CELTA to be ahead of the game and get a job.
If you speak well and are sociable you can teach privately without playing the school games. Don't be discouraged by those trying to carve out their domain and keep you out
Herein lies the problem to our attitude to non-qual teachers. You seem to have a sensible head on your shoulders and I've no reason to doubt you are an effective teacher, which you probably are. But the phraseology of what you said above is dangerously misleading. A qualified teacher would never say "if you speak well and are sociable you can teach privately without school games" because, unintentionally, you've demeaned all the training and education we've had in a single sentence. What that sentence means to me (as someone with years of experience) and other teachers is "chat, be a nice guy for an hour, earn some cash". You don't mean that, but that's how it comes across to us and everyone else. If you said "If you can understand your student's needs and interact with them and use your experience to help them develop their language skills" which is probably what you meant it suddenly sounds a lot better.
(I haven't got, nor ever hope to get a DELTA btw. God knows how a DELTA qualified teacher would phrase the above.)
I'm not trying to bust your balls, I'm just trying to make you see it from our side.
As regards students, there are thousands - I can't think of anyone who marks out his/her plot.