If a person wants to take upon himself an additional minhag that his parents don’t hold of cause their not as serious as him religious wise he can add what he wants and move up in life.
So you think it’s an insult if your father doesn’t wear a gartel and you decide to start wearing one? Is your father going to even know or see you wearing it? Which orthodox parent would get upset if their child decides to take upon himself additional minhagim that they don’t keep but he wants to be more serious and orthodox then them? Maybe reform Jewish parents won’t like or allow it but a regular orthodox Jew should be proud that their child wants to improve in their religion.