I have seldom if ever talked to these christians.
I have however talked to pagan's who laugh at these people. Apparently speaking in tongues is thousands of years old and originates from pagan spirit communication, during rituals, the spirit would take over somebody and send out a message in tongues.
Apparently the confusion comes from a scripture saying somebody would come and teach a new language, unlike one ever used. Biblical scholars from hundreds ad were trying to figure out what this was, heard of speaking tongues, and thought of it as a language unlike they had ever heard before, and wrote it in to translations without doing more research.
According to pagan's they could identify the spirits causing baptists and other "tongue speakers" to think they are in a holy spirit, but because of the general hate they feel they are given, would rather not let them hear the pagans actually have the same rituals but do them less often and with more reserve because as a culture dealing with spirits for thousands of years without the protection of something higher, they've learned doing these things often leads to problems down the road. If christians were more caring towards them as people they would tell them these things but hate of them leads to hate of you.
I realize this is not from the group you asked for but this is what the other group who does this says about the practice.
I think the perspective is useful which is why I share it with christians despite the source of the information