You misunderstand. The problem is not getting married to defy parents. You are being intentionally daft. It is to keep parents from getting between couples after they wed. I wish my former in-laws had taken that one to heart, from what my former wife says. The problem our Lord was addressing was parentally inspired divorces, not homosexuals. The people questioning Jesus did not ask that question and had no reason to do so. Jesus did not have Donald Trump moments where he spoke gibberish in response to what was asked. If this is your argument against homosexuality, then you have no argument about homosexuality.