Interesting perspective, but I don't think that it is an attempt to market-grab by Microsoft.

There is a legitimate market for a distributed caching framework that Microsoft is trying to fill. A lot of the solutions out there that can be used in an IIS/.NET environment are ports from other platforms. While it is great to have choice, it is also nice to have a product built from the ground up by a team that knows the ins and outs of the target platform and can exploit any performance and stability gains. Not trying to take away from the other projects/products out there, but knowing that I could have a similar product from my framework/tooling/operating system vendor is very attractive in terms of integration and support.