You can't generalize that statement.

There is a very valid reason why the Creator of erlang back in the day said something along the line of "you need to iteratively remake your software, improving it each time"

As your knowledge about a topic grows, your initial mistaken implementation may become more and more obvious, and it may even mean a full rewrite.

But yes, a person which instantly says "rewrite" before they understood the software is likely very inexperienced and has only worked with greenfield projects with few contributers (likely only themselves) before.