See, this is kind of what I don't get. Why the need for official licensing?
As a user of HeroLab, I can say that it works quite well, and the limit to the SRD material has been addressed through the community packs. I was all in for $40, for the program, and then for the 5E access. HeroLab is a character builder, monster builder, and encounter tracker all in one. It doesn't do encounter building in the sense of CR and experience point budgets and the like, but it allows you to load all the monsters you want into one encounter, then add your party, and boom your encounter is ready to go. You can roll initiative and then proceed in order, entering hits and such as you go, and it will track everything you want for you.
I can also get Roll 20 for free if I need a VTT, which is free. Or if I really wanted to splurge, I could go without Fantasy Grounds, and buy the adventures that I wanted to run.
These tools already exist, so to me it's smarter for WotC to let the third parties create them and to support them rather than to try and compete with them. These are quality programs...trying to make an in house version that would compare would be a huge investment of time and resources. And judging by the fact that they never got it quite right the last time they tried, it seems smarter to avoid.