Players use controllers for PC all the time. But using a mouse and keyboard on console is a bit more rare. In games like Overwatch, such use can provide a distinct advantage, and Blizzard has come out strongly against the practice.

In a thread on the official forums asking for clarity on the issue, Game Director Jeff Kaplan said the Overwatch team "strongly objects" to the use of mouse and keyboard input on Xbox One and PlayStation 4, and that the company has contacted both Microsoft and Sony to "express our concern."

"We have lobbied and will continue to lobby for first-party console manufacturers to either," he said in response to the query. "Disallow mouse and keyboard and input conversion devices OR Openly and easily support mouse and keyboard for ALL players. I encourage you to reach out to the hardware manufacturers and express your concerns (but please do so in a productive and respectful way)."

Kaplan clarified that he sees this as a problem for the team, but cannot solve the issue "without help from our partners."

Phil Spencer, the Xbox head honcho at Microsoft, chimed in on Twitter. "Clearly in some cases M&K is an advantage. I'm a fan of giving the tools to studios and they'll do what's best for their games."  

Using a mouse and keyboard for shooters traditionally offers better control and pinpoint accuracy for people using them, and the initial compalints on the Overwatch forums were lamenting that most of the top players appeared to be using them. Consoles do not inherently support them, and an input conversion device is needed to allow it. Microsoft has said previously that they intend to eventually offer mouse and keyboard support for Xbox One, but have not given a timeframe. Sony has not officially spoken on the issue, although it has licensed similar products that work like a mouse and keyboard, but just emulate the controller.