No, it's really not. Pretty much all large patent portfolios get licensed this way, and always have been. There are a multitude of legal, technical, practical and business reasons, but that's how it goes.
It's just that some companies don't like to pay what's due, which is fine... It's their right and they can settle it in negotiations or in court. The problem is, due to the current media atmosphere that is conducive to inflammatory rhetoric because it garners rageviews, these companies now also like to complain loudly using words like "extortion", which the tech media eagerly parrot. And then others who don't like the licensor (or patents in general) pick up that rhetoric and run with it.
That's just one patent that got invalidated. And that required Google to identify one comment from more than a decade back to argue that the patent was obvious (rather than anticipated). All that to kill a single MS patent.
MS has hundreds, probably thousands of patents in their portfolio. A single patent makes negligible difference to the portfolio.
In addition, MS has prevailed in court with several other patents in many other jurisdictions, so clearly they have enforceable patents in their portfolio. That is why they can rightfully continue asking for licenses.
This is one of the "practical" problems of licensing large portfolios that I alluded to. The quality or fate of a single patent does not reflect on the entire portfolio. Conversely, invalidating each patent or valuing each patent is also incredibly complex.
There is an entire field of specialization for valuing portfolios. Calling it extortion is mostly the efforts of one side of the table to exert indirect pressure on the other
What Microsoft does is very different to that and very arguably close to the definition of extortion.