The monopoly/monopsony distinction is pedantry. The important point is that consumers and developers suffer because one company controls access to the lion’s share of a market. That point can be criticized and debated, but litigating semantics makes for boring reading and anyway it’s off topic.
Expecting people to be in the general ballpark of the definition of a thing isn't pedantry. It's kind of hard to have any sort of meeting of the minds when people ignore even the basic premise of a term.
Most competition regulators disagree. 50% of a market is well above the threshold for both the US and EU to consider a company to be a monopoly. They usually treat the cut-off as around 20%.
