A family relative possessed of a long history of willful foolishness recently objected to my wife's fondness for roasted beets on the basis that beets are bitter.
Now, it makes me no nevermind what other people want to eat. I think beets are delicious, but you are free to disagree. You can dislike beets for any reason you choose, or even no reason at all. You can have a general opposition to shockingly red foods or things grown underground. You can dislike the texture of beets, or find the flavor off-putting. I won't tell you that you're wrong for disliking beets, whatever reason you may have. But if you tell me that a roasted beet is bitter, at that point I'm pretty sure that you're just making shit up to avoid trying a beet.
Beets, as anyone with even passing familiarity of the sugar industry could tell you, are an exceptionally sweet root vegetable. Roasting, as anyone with occasional experience in the kitchen knows, brings out the sweetness in a vegetable. Roasted beets are sweet enough to be a desert, only more virtuous. Roasted beets possess any number of attributes, some good and others bad, but they are by no means bitter.
This relative who was so bothered by hypothetically bitter beets is not a reliable source of information of a culinary (or any other) sort--not because of a lack of intellectual ability, but due to a lack of curiosity. Calling it a "lack of curiosity" actually undersells the situation, which is more of an affirmative campaign against anything novel or new than a mere disinterest. Decrying beets as bitter wasn't a description of their flavor so much as an assertion that they were unfamiliar and, therefore, suspect. We could roast a panful of delectable beets, but no evidence of their sweetness would change this person's opinion. Beets will be forever bitter.
This applies to more than roasted vegetables and to people beyond my family.
Someone who thinks a beet will be bitter won't take a nibble; even if cajoled into trying a bite, the taste will be foul. You can't change a closed mind. Contrary evidence will lead to a new theory with the same old conclusion, not a change of opinion. Whether the mind is closed against a side dish or a poem or a story or a song or a career, closed is closed. Not everyone will enjoy your cooking. Not everyone will enjoy your art. There's no accounting for taste, but sometimes taste has nothing to do with it.
That doesn't mean you're a bad cook. It just means that you have the wrong dinner guest, so ask someone else to come over.