The reason people are conservative on here is there is a lot of collective wisdom on here, people who have been through the process, been around a lot of people who have gone through the process, and they are trying to both be realistic and encouraging. If people don’t outright tell someone “you don’t have a chance, forget music, go become an accountant” it is simply trying not to be harsh, among other things, when you face with music far too many people who say “what do you want to waste your time with music, there is no future in it”, people tend to try and be nice. It isn’t politically correct, it is simply realizing that the people asking questions here may be mistaken about the path into music, but they have a dream and people don’t want to be cruel, even though music itself can be.
As far as the population on this board being in a different world then you live in, I have no way of knowing what your ‘real world’ is, but there are people in here with a wide range of experiences, with a variety of music programs, whether they/their kids went there or not. There are people in here who have kids in the top conservatories, people who have kids in music schools inside big universities at a high level, people with kids who went to schools different from those, and as far as I can tell, that is the ‘real world’. Many of the people who post in here have been involved with high level music students and music education since their kids were in middle school, and have been around a lot of other serious music students and saw what they went through. There have also been people who have posted stuff on this board they claimed was true, bomb throwing (really lovely thread about Juilliard and its admissions process was a classic), that quite frankly flew in the face of experiences of a lot of people on here, and usually it turns out the person was either looking to stir things up, or was basically projecting what they believed to be true.
The other reason people are ‘conservative’ is they realize that what they know may not be universal truth, they are talking from what they have experienced, what people they know and trust have experienced, but they also recognize it is not a one size fits all world. The real world is a funny place, it is not one world, it is a world full of a myriad of smaller worlds, each very different. Sure, I have seen kids come on here who I think have zero chance of making it into a decent music school, kids who are so deluded it isn’t funny (when I hear someone say things like “I did an audition, and the audition panel clapped and told me I was another Paganini”, it doesn’t exactly ring true, more often then not I hear “the audition panel was friendly, asked me about myself”, and a lot of the times they find they didn’t get in…
"But if a teacher does not have a say in admission, he or she normally would not contact a student without him/her contacting the teacher first. "
That simply isn’t true in all cases,or even a majority, and here is why, it totally depends on the program and how it is run. In a program where there is only a single teacher and that teacher decides, that is probably true, but that is not how every music school works, and in the bigger programs admission is based on a panel, if you get through that then a teacher has to a)want to teach you and b)have room in his/her studio. Want to know a dirty little secret? Sometimes a teacher really wants a student, but then they are told by the administration they don’t have room for another student, it happens all the time. The teacher could contact the student, and then find out they don’t have a slot. A teacher at another program may like a student a lot, call them to see if they are interested, and find out that the school literally decided they couldn’t admit anyone new (yep, schools do audition even when it looks like they have no openings). Teachers have a say in admission, but in many schools it is not a direct say, if they like a student and the panel for the most part doesn’t, they won’t get in, and a teacher could call the student assuming they would pass the audition then find out they failed; a teacher may think they have room in their studio, call up the student, but then find out a student they thought might be leaving decided to stay, they may simply not know. Depends on the instrument,too, it may be very different if it is the violin or piano department, which often have multiple teachers (for example, at Juilliard, you might have 9 or 10 teachers on a panel for violin) as opposed to brass or woodwind where it will be smaller.
The reason going back to the OP is that many of us have seen cases like that, both reported on here, and in real life, many of us have been on this board going back more than a few years, and that experience also guides what we say on here, because we know our experiences aren’t everyone’s, and how wide a range of experiences there are, and how hard it is to say things like “If a teacher gets in touch with you, that means you are in”, because in more than a few cases, it may not mean anything. Believe it or not, like the infamous letters after you audition, teachers do marketing and promotion, too, if you have a teacher at a program that isn’t necessarily well thought of as a music program, they may need to self promote to try and get kids to sign up with the school and him/her, because the lack of reputation for the school hurts them…and they could call a lot of kids, in order to try and fill their slots, you never know.