There are lot of wonderful teachers in this forum like 5jj, Rover_KE, emrs2d2 etc
Generally, however, the system works. Non-teachers who make a point of following forum guidelines and admitting that they are not teachers show us that they are honest, and that their answers should not be accepted automatically. Members who visit the forum regularly soon get to know the 'not a teacher' members who can be trusted. If people who claim to be teachers regularly give unhelpful answers, we do ask them stop answering questions.
Don't forget that some of the questions asked cannot be answered definitively. There is no 'Academy' to regulate English; sometimes even those of us who are native-speaking teachers can do little more than give our opinion. In such cases, a non-teacher's opinion may well be as valid as a teacher's.
Does teacher means that they are a real teacher teaching English in real life?
I have a suggestion, why not put the word "Teacher" under the username of teachers. For example, 5jj has the word Moderator under the username. If 5jj is a teacher, you can put 5jj, Teacher, Moderator
Is it that important to you to know whether someone is teaching English as a profession? I only ask because there are non-teachers here whose grasp of the minutae of the English language, and their way of expressing it, is phenomenal. There are teachers (mostly native speakers and some non-native) whose knowledge and advice is occasionally less impressive or useful than that of the non-teachers.
If you click the words "Member Info", two lines beneath a username you will find this information anyway. Yours says "Student or Learner", mine says "Teacher". I teach much less than I did when I worked in Madrid as a full-time English teacher but I still have students. I am more than well aware of the fact that quite frequently a non-teacher's answer is much better than mine.
I am just curious about the word teacher only. I actually thought maybe someone has to pass through some test in this forum to become a forum teacher. As long as the answer helps, I am happy about it. I actually thought if someone is a teacher, they could just display Teacher . And if someone is a student, it could display Student, and anyone can also add the "Not a teacher" under the username, just like the word "Moderator", one look at it I will know it is a moderator. It will make the forum cleaner as there is no need to always repeat "not a teacher" all around the forum. Just a friendly feedback only, can ignore it, maybe I am the only one who is confused about this "not a teacher" thing.
Just out of interest, where would a Pre-service teacher be listed in all of this? Technically speaking a Pre-service teacher is still a teacher...