So apparently despite a Lync 2013 release delivering signifigant improvements to MSFT UC’s mobility story (VoWiFi/3G), voice and video interoperability (H.264), resiliency options (SQL mirroring, paired SE’s) and SKYPE FEDERATION, Cisco’s UC solution has gained in its already dubious lead over Microsoft’s best of breed solution.
Lots of Lync deployments occur in large part as migrations away from Cisco UC.. i’ve not heard of any going in the other direction (and user experience wise can’t see any reason why you’d ever want to), so can only imagine this quadrant reflects legacy (CIO or analyst) vendor allegiance. Grain of salt.