Friend,
I think this may be a bit of an overstatement. I am not a cessationist, yet I agree with everything you've been saying here. And I strongly disagree with your opponent.
As far as tongues go, I whole-heartedly agree that tongues refer to known languages, not some kind of gibberish-speak. Also, I firmly agree that witnessing, sharing the Gospel, etc. is how we must engage our various cultures, not by miraculous so-called "sign gifts."
However, I do not think one has to be a cessationist to agree with what you've been posting here recently on this issue.
The way I answer the question about cessationism (or the lack thereof) and tongues is this:
If I were having a Jonah moment and the plane I was on was flying over Africa and I were somehow sucked out of the plane and survived the fall, is it possible that God could grant me to understand the language of the tribe I land upon, or is it possible He could grant that tribe to understand my language? Yes, absolutely. Is it likely that this type of thing will happen? No, not at all.
The problem with the "Charismatic" view of tongues we see today, as you have rightly noted, is this: It becomes a dividing line between Christians and it does split congregations. My thought is this: It isn't an issue of cessationism; it is an issue of Christian maturity. But, I don't buy the "private prayer language" thing either, unless, of course, it is a known language. If you, for instance, were here in the US and there was a cataclysm of sorts in Japan and you were in private and decided to pray in Japanese to feel closer to your adopted people, that would be proper. To be in private and speak gibberish is improper.
In any event, I think it too general to say that all non-cessationists are lumped in with the Azusa Street tradition of nonsense. It's like the "Good Witch" Glinda asked (with a modification): Are you a good cessationist or a bad cessationist?
Blessings,
The Archangel