Interesting article below from EXASOL that is successful, continues to grow at a laudable pace, maintains its ability to execute and vision and yet after 5 years inclusion was dropped out of the 2017 Gartner MQ.

The reason- the revenue limit for inclusion was raised. So you have to be "big" to be in. Many SMEs may prefer a smaller vendor so as to be important enough to have its voice felt. a $35m a year vendor can be as stable and reliable as a $350m p.a. supplier. Some may argue even more so. 

I have already argued that Gartner is only one source of information when short-listing technology vendors. Smaller analysts will look at smaller and perhaps more innovative vendors. Gartner Analysts have no monopoly of wisdom or information and maybe biased in their view of the world.

Nevertheless, when you look at the individual vendor reports in each Gartner MQ you can see the rigour in analysis and SWOT presentation. It's just that you'll miss some very good options unless you widen your research.