Those are two things that I would never say together. Lync is great if you are all on Windows within the same building or campus perhaps, but the video quality is horrible compared to Google Hangout or (consumer) Skype for cross country and international communication.
Also: Lync is now called "Skype for Business" and old Lync will be sunsetted per http://research.gigaom.com/2014/11/microsoft-announces-skype...
Next time you want to defend the full Microsoft software suite, just don't mention Lync and Sharepoint, and your argument will do better.
Sharepoint just generally sucks because it's a platform for building one-off custom apps that part of your accounting department uses. Any platform with that use case is going to suck. But maintaining a Sharepoint environment is a lot easier than maintaining 30-40 individual web apps running on separate Linux machines, and it's a lot more maintainable of a business process than doing everything in an Access database or a shared Excel file.
It's also just flat-out ubiquitous. It really doesn't matter how much Sharepoint sucks because nearly every company uses it in some form.