All sorts of things happen in spoken English.
The meaningless phrase "Well, I think" is informal phatic language to avoid sounding dogmatic. It is very common in spoken English, but not in written English of any degree of formality.
The phrase "the older ..." technically modifies "times" with "when," "where," or "that" dropped. That kind of ellipsis is common in spoken English. In written English, ellipsis of conjunctions is rare, and "that" in this context is probably less common than "when" or "where."
Dropping the noun from an adjective-noun combination is not frequent in English, and dropping the noun from adjective-and-adjective noun is something very seldom heard in US speech that I can remember. However, I doubt that the intended meaning is that older but inexperienced people were criticizing the younger but experienced people so "older" might sound a bit weird in either spoken or written English.
In short, the sentence is acceptable, but not completely natural, in both spoken and written English.
Here is what would sound more natural in spoken English:
Well, I think it's one of those times where the people with more experience were criticizing those with less experience.
In more formal written English, I would find very natural:
It was one of those times when the more experienced were criticizing the less experienced.