Usage of a commonly accepted proverb to disregard someone's opinion

Question

I am looking for a term (or a sentence) that would describe a figure of speech where one individual use a commonly accepted proverb (or thick concept or other) in order to disregard someone's opinion on the matter.

Example

Obviously some things look better than others. If for example we consider two cities one commonly considered ugly, one commonly considered pretty, and ask 100 people which city they find more aesthetic we have likely to have a result very far from 50:50.

Yet, the proverb "beauty lies in the eyes of the beholder" can be used in a speech to disregard one's personal opinion about aesthetic as being too subjective and to not matter as would not represents most people's opinion.

Alice: I went to this restaurant last week. The food was sooo bad!

Bob: Well you know... There is no accounting for tastes! You may not like it but that's only your opinion.

In such circumstance it will be hard for Alice to convey her point as she would necessarily appear as being not open-minded (whether the ratatouille was burnt and the vegetable rotten or not) to the eye of her audience. How do we call (or describe in a few words) Bob's figure of speech?

Answer 1

In the example, Alice is likely arguing that the food at a particular restaurant is bad because it was bad last week. Bob, who makes no claim of specific knowledge (like having also eaten at that restaurant last week), inserts something irrelevant to the conversation, and that thing can be called a non sequitur:

non sequitur

2: a statement (such as a response) that does not follow logically from or is not clearly related to anything previously said

Why is Bob's response irrelevant? Bob's comment derails the argument from any quality of the food to a quality of the person discussing it. This is an ad hominem response:

ad hominem

2: marked by or being an attack on an opponent's character rather than by an answer to the contentions made

Was Bob responding to the contention that the food at that restaurant was bad (in taste, quality, etc)? No, Bob effectively said that the person tasting it can't be trusted, which is irrelevant because Bob does not bring up why Alice cannot be trusted (ex: that she famously dislikes food that everyone else likes). Without evidence for either the quality of the food at that restaurant being good (contrary to Alice's argument) or the quality of Alice's taste being untrustworthy, it's irrelevant to the discussion to bring up what Bob brings up.

Answer 2

If you consider famous movie lines to be commonly accepted expressions, here's one from The Big Lebowski starring Jeff Bridges, and the quote is:

"That's just like, your opinion, man"

Origin described by Know Your Meme

The phrase originated from a memorable dialogue scene in the 1998 cult comedy film The Big Lebowski. In the scene, the main characters The Dude (played by Jeff Bridges) and Walter (played by John Goodman) are approached by Jesus Quintana (played by John Turturro) who taunts them both before, to which The Dude replies “…that’s like, your opinion, man.”

Answer 3

Jerry Garcia described peoples taste for his band the Grateful Dead like this:

• “We're like licorice. Not everybody likes licorice, but the people who like licorice really like licorice.”

One way to ever so slightly tug at someone's sophistication(depending on the situation) while making clear there is room for a difference of opinion is:

• "It is an acquired taste."