‘Thank you’ has an exceptionally special place among ‘good’ words used as irony?

A. A. Milne, best known for his books about Winnie-the-Pooh, is much less noted as a prolific playwright of about forty plays. They are carefully crafted works that continue to entertain and delight readers and audiences of all ages in UK, but not in Japan. I have recently translated some of his plays into Japanese in order to revive his plays and introduce them to Japanese theatre lovers. Among his plays full of humour, warmth and kindness to human beings, I came across some instances of ‘Thank you’ used in an ironical way (dramatic irony?). This is a little surprise to me, but what is more surprising is the fact that this ironic meaning of ‘Thank you’ is entered in Oxford Dictionary of English (2003): ‘used ironically to assign blame or responsibility for something,’ while the compilers of learners’ dictionaries are wise enough not to enter this ironic use. Some ‘good’ words or phrases are known to be verbal irony. But I am wondering if ‘thank you’ has occupied a special place among such expressions as you know, great, funny, and nice (the latter two having an entry of ironic use in ODE). Reflecting my speech acts in my own tongue, I have noticed that some ‘good’ words can be used ironically almost in any situation. And in every corner of the world, there have been some cynical people around us. Irony is universal? Every word Dr. Johnson spoke may have had an ironical or cynical touch of meaning. An entry in his Dictionary: Cýnical, Cýnick: Having the qualities of a dog; currish; brutal; snarling; satirical. Does ‘thank you’ have an exceptionally special place among the ‘good’ words ironically used? If so, could you help me have some, if any, explanation or reasons for its frequent use among British people?