That tends to be the biggest cop out excuse for libraries. Just do a major version release. The fact this library lies about the encodingis extremely problematic and causes numerous bugs. Any program currently using this library is already incorrect because of this behavior. Actually exposing the problem makes it easier for people to fix.

Agree, but we're stuck with API compatibility for a good while.

Also, the chances of breaking something are really high, because not even you remember how the code actually works.

Why are there so many programming languages and frameworks? Everyone has their own opinion on how something should be done. Some of these systems, like AOL, Yahoo, etc... have been around for a decade, and probably not updated much.

It gets worse when you're working on a team. No-one dares touch styles authored by someone else, because it's often unclear what they're doing, what markup they apply to, and what disasters will unfold if you remove them. The consequence of all this is the append-only stylesheet. There's no way of knowing which code can safely be removed, so it's common to undo some existing style with another, more specific style — even on relatively small projects.

In the real world — the time to pay off technical debt is scarce — in most of the time fueled by the fear of the unknown. The management loves to milk the cow but not to change the litter. The developers on another hand avoid modernizing legacy code — to avoid trouble in case anything breaks.