The company I am at uses IE10. IE11 does not work well with some of our own websites along with client sites. I do not know what Microsoft did to screw up IE but we have had this issue since IE6 and every version afterward.
Microsoft generally does not care what other (non-microsoft) products are adversely affected by any of their “upgrades”, so long as their OS and Office flagship products are able to evolve to the point where other company’s products must figure out how to change enough to work with the latest iterations of those programs or run the risk of being defined as “obsolete”.
It seems to have worked out rather well for them thus far...