The thing is, Lync got renamed to Skype for Business and had a UI makeover to match Skype's Fisher Price UI (the one that got introduced when MS bought it and version numbers started getting shooting up for no good reason).
At the same time, Skype has just had a Snapchat UI makeover on mobile and Desktop will follow. It makes Skype's UI even worse, if that were possible.
What does this mean, that Lync will also get a totally unusable Snapchat UI makeover in a later Office version because marketing insist both programs be called Skype and look more-or-less the same?
Meanwhile, audio problems, group chat problems, headset problems, stupid messages saying stuff might or might not have been delivered, false presence info (online/away), file transfer, single thread UI, lack of shared chat history between devices, etc... still make Lync a crappy experience.
The best chat program MS ever did was MSN Messenger, but it seems nobody at MS even remembers it.