All of it was pretty useless compared to using Envy/Developer which was a unique version control system that was based entirely around Smalltalk and collected up your changes in a way that made sense for sharing.
The guys at ParcPlace never seemed to quite understand what we were facing back then - your average departmental programmer trying to replace a green screen in a team of 20 other programmers not only had to cope with a complete change of paradigm for the programming language, but the version control systems were non-existent or useless even compared with simple systems like SCCS. Change logs just didn't cut it when you got past 2 developers.
The vanilla VisualWorks simply didn't scale to multiple users trying to share code. Envy/Developer fixed that (and how! Still the best version control system I have ever used).
The "forever" thing might be an exaggeration, but in practical terms I had a lot of guys destroy images accidentally by over-ridding something in Object or whatever while they were learning and causing havoc for themselves. Trying to piece together their good work from the change log was...effectively impossible until they learned what they were doing due to the total scattergun approach a lot of them used. So perhaps not "forever", but given the time constraints in a normal development environment, it was forever for certain values of forever.