[FROGGS]

Exactly. So you always have two choices:

1) Just update a little step by step. Here you would keep your userbase until there is a piece of software after a decade that will take a high percentage of that userbase.

2) Do a rewrite that takes three times longer than planned and split your userbase in half for the old and the new version. You can just pray that the new version is worth it.

So in a sense you will do the wrong and the right thing at once.