Please explain how it could be worse to follow the Torah than to change a minhag.
This is nonsensical, circular logic, or gruesomely misleading (but still nonsensical). By definition, if Mesorah (or anything else legitimate halachically) says something, that is what the Torah says to do; that is following the Torah. The comparison that you can make, if this is what you meant, is between following whats written/stated b’feirush in the Torah, but devoid of any other context, and changing a minhag. However, that comparison is absurd because being written in the Torah does not give it any “chumra” over a minhag vis a vis whether Mesorah talks to it (besides for the language being criminally misleading by expressing “source for the mitzva” as “following the Torah”).