Ideally speaking, we are not supposed to look for the root of innovations or things that go against the Sunnah. We are supposed to follow the Sunnah without any need to look for justifications to those who don’t.
To the best of my knowledge, Imam Malik Ibn Anas was once tortured in jail by one of the rulers for not saying what he likes. This led to his hand being partially paralyzed and he couldn’t lift it to his chest while in prayers. That is why people thought that this was part of the Sunnah
and Allah knows best.