We don’t want to diss the language, it’s well bad as it is, but:
If bad means good, I will be confused.
I have read somewhere that “it is interesting.” means “I am not of the same opinion.” How do you usually reply if you receive this comment?
“It is certainly interesting . . . (but . . .)” is often used by teachers who do not want to discourage their pupils by saying “that’s really, really stupid”.
Depending on the context and tone of voice one can choose all sorts of replies, from the profane to “let me see what else I can do with it” or “I am so pleased that you like it” - the latter reply may be evidence of self-delusion or sarcasm.
N.B.: Not everyone uses “that’s interesting in this way”! Depending on context and tone of voice it can be meant as a genuine compliment.
Many of the young people in Japan use “ヤバイ(yabai)”–literally means “dangerous” or “chancy”-- to show praise or enthusiasm to something. I hate hearing this interesting expression. They might be surrounded by many dangerous things; I don’t want to get near to those young people.
(Edited)