Even aside from the rabbonim who said Tendler is a rasha, simple logic says that even if he had a right to his own shitta — no one is forcing him to perform MBP on his children — yet he clearly and absolutely has no right to force others — who b’shitta hold MBP is absolutely halachicly mandatory — to follow his “shitta” not to perform MBP.
And even far worse is his mesira of getting the government involved in his attempts to stop Yidden from following their halachic shitta that it is mandatory.