Changing one’s mind isn’t always good. You can absolutely change your mind to a worse position, and nobody should applaud you for that. In this case, I don’t actually think that Biden has ever had strongly held personal beliefs about this issue or really any others. This is typical of politicians. You can pretty well tell when someone has genuinely held principles (they change little over time), and if they genuinely change their minds, they will usually explain in detail how it happened. That is definitely not what’s going on here lol.