Riiiiiiiiiight... Nice rationalization. And I believe you believe it.
But let's see what you actually did in your "musing." (BTW: these are just my musings on your musings.)
What does it mean to say, "It [almost] never happens when you are alone." It appears to mean that it's usually done for some public display. So, what does that say about the perception of the tongues-speaker's character except he is pretentious.
What does it mean to say, "It happens [almost] only when you are with a group who believe the act is God-inspired, and to be admired." (I added your caveat here as well.) It appears to mean that it's usually done only in the company of those from whom one might because of it receive some measure of esteem. In other words, it's a means of either self-aggrandizement or ingratiation or both. What does that say about the perception of the tongues-speaker's character except that he is egocentric.
What does it mean to say, "The quality of the pronouncements improves greatly with practice. First attempts are more "oola, oola, galla, bamba." Then sophistication sets in, and you hear, "Bashaga, cobalindo, perterino, vestiblularoni." It appears to mean that the person is either self-deceived or a deceiver. What does that say about the perception of the tongues-speaker's character except that he is a liar.
What does it mean to say, "Private prayer language may result when a pious follower of the procedure hears about objection No. (1) above, and seeks to reject the validity of the criticism." ...sorry, but I don't know WHAT this means.
What does it mean to say, "Any psychological analysis of the practice indicates understandable and cogent explanations of the event." And what would those be? This is similar to the tactic Bultmann and others used -- and many still use -- to try and discredit the accounts of "supernatural" events in Scripture along with the possibility of the supernatural in the real world.
What does it mean to say, "As always, belief in inerrancy, and selective belief in individual verses, enhances acceptance of the manifestation as proof of spirituality. In turn, speaking in tongues provides another attainable goal in the quest for certainty and assurance?" It is quite interesting that you consistently lump together fundamentalists, inerrantists and charismatics. The truth is, most fundamentalist groups are also cessationists, which oddly enough forces them to take liberties with Scripture they otherwise would eschew. On the other hand, charismatics are rarely fundamentalists except with regard to legalistic application of dress codes and such, but most charismatics are not really inerrantists, either, in that they believe through tongues-speaking, prophecy, words of knowledge, words of wisdom, etc., more revelatory light beyond, but not in contradiction of, the Bible will be given. Among non-fundamentalist, evangelical inerrantists, however, there is often some openness to, if not acceptance of (i.e., W. Grudem), tongues-speaking and other manifestations of the Spirit.
But it must be noted that if, as you posit, "speaking in tongues provides another attainable goal in the quest for certainty and assurance," yet those who practice it are so deceptive or easily deceived, there can be little if any certainty -- and this is especially true given that most charismatic groups do not hold to a doctrine of the perseverance of the saints that includes eternal security of the believer (in other words, they believe one can lose his or her salvation).
Thus, your musings do give one a sense of antipathy toward tongues-speakers. Nevertheless, perhaps in your magnanimity you include them in your circle, but it seems to betray a sense of elitism, which behooves you to try to "help them understand a better way to interpret, serve and act."
Just a few thoughts for Oldad from a YoungPup.