I really doubt that vendor lock-in is the reason in their case. Heaps of other organisations - including many not particularly competent public sector ones - managed to do it. Back when everyone was doing it (15-20 years ago), there was a whole cottage industry of consulting firms specialising in Novell-to-Microsoft migrations. So long as you were willing to spend sufficient $$$, and had sufficient executive buy-in, you really couldn’t go wrong. I suspect in their case the real answer must be either (1) unwilling to spend enough to successfully pull it off; or (2) never made it a priority at a sufficiently senior level (or both)
Lotus Notes came with a comprehensive development environment for custom applications - much easier to get locked-in there. GroupWise was much more spartan in its feature set, just email and calendar. It had an API but few customers ever wrote code against it - it was primarily used by third-party vendors for integration with document management systems, anti-spam/anti-virus, email archival, eDiscovery, identity management, etc - back in the day, most of the big enterprise offerings in those spaces had plugins for GroupWise. But sooner or later they almost all had plugins for Exchange too - so very rarely would that be a blocker on migrating GroupWise to Exchange
And being hooked on Microsoft might not be the best place to be-but still better than stranded on a dying platform. At least Microsoft has a clear roadmap to move to cloud (if that’s what you want to do), By the time cloud became a thing, GroupWise’s remaining install base was too small to support that
Lotus Notes came with a comprehensive development environment for custom applications - much easier to get locked-in there. GroupWise was much more spartan in its feature set, just email and calendar. It had an API but few customers ever wrote code against it - it was primarily used by third-party vendors for integration with document management systems, anti-spam/anti-virus, email archival, eDiscovery, identity management, etc - back in the day, most of the big enterprise offerings in those spaces had plugins for GroupWise. But sooner or later they almost all had plugins for Exchange too - so very rarely would that be a blocker on migrating GroupWise to Exchange
And being hooked on Microsoft might not be the best place to be-but still better than stranded on a dying platform. At least Microsoft has a clear roadmap to move to cloud (if that’s what you want to do), By the time cloud became a thing, GroupWise’s remaining install base was too small to support that