Whenever you make a change, someone somewhere will have problems with it! This is why we do updates in incremental fashion, so people can report the problems and we can fix them.

Improvement is always necessary, because no matter how many people say everything's just fine as it is, there's equal numbers of people having problems that you just don't see (whether those problems are bugs, usability problems, accessibility problems, or things just not working as well as they could). For instance, replacing all the Javascript used to run your journal with jQuery, a more modern Javascript library, allows us to have access to a lot of the development being done by the jQuery team, which means that we don't have to try to fix all the problems ourselves; we can take advantage of the development time other people have invested in the system. The old Javascript used in your journals was written a very, very long time ago, and we've been seeing multiple reports of things not working in newer versions of browsers because the standards have moved on. Switching to jQuery means that we don't have to spend all that time debugging problems with the old Javascript libraries: the people who develop jQuery do the browser testing, and we get the benefit of their work.