IBM has bought out resellers in the past. Mainframe business is lucrative. There's only a handful of companies (literally) that sell IBM mainframes in the US. They're EXTREMELY expensive and the initial figure is often the cheapest part of any client's investment. The Texas Dept. of Corrections uses one & they basically pay per cycle. Reoccuring costs. IBM does have a direct sales option, but due to lawsuits in the past they've had to change the way they do business to make it more friendly for these resellers do reach out to customers. IBM has gotten into trouble with resellers and mainframe partners in the past.
I'm also a big IBM customer. I've got a few IBM reps that work out of my office a few days a week, and also work with their resellers (which mean Kruse's competition). I know their hardware business, their software business, their professional services, their insanely profitable support business, consulting services, presales engineering, etc..
IBM does have a monopoly in the mainframe world. There's nothing else that can compete with the amount of power these things have for the enterprise.
IBM consolidated 15,000 redhat linux servers on just 3 mainframes over 6 years ago. Imagine what they're capable of doing now. If you're familiar with Moore's Law you'd also understand that the capacity of technology doubles every 18 months, and the same can be said about the price in niche solutions like this.