The thing I am seeing there is rather a dislike of the codebase than a desire to rewrite.

My rule of thumb is this: you need to touch a codebase _more_ to throw it away.

Tell that to whoever wants to rewrite. You will have to maintain the old application anyway (yes, this is a given, you are not getting an exemption for security holes) and you will have to de-risk the project by providing value (== release early, release often, continuously switch parts over - which requires work on the legacy side, too).

If someone wants to do a big bang rewrite then you need to fight for the importance to touch the "legacy" codebase. That is the actual reason why people are so religious about their rewrite.

Other than that: same thing, ~20 years and nothing good comes out of big bang rewrites and releases.