No, he is not misleading people or even lying as someone else was suggesting. First of all, he did not create this statistic, StackOverflow did. You know, based on the hundreds of thousands of people they surveyed.
Yes, macOS has a single bar for all versions — just like Linux. So at first sight, the graph is difficult to decipher and, I’d argue, not designed very well. But it clearly shows four bars for Windows, each clearly labeled. It clearly shows the true market share in percentage — no matter how big each bar is, macOS is clearly labeled at about 25%. Which obviously means it’s not the number one.
And you can’t really criticize a statistic if you only look at the graphics and ignore the text. It clearly states: “Last year, Mac edged ahead of the Linuxes as the number 2 operating system among developers. This year it became clear that trend is real. If OS adoption rates hold steady, by next year’s survey fewer than 50% of developers may be using Windows.”
(Emphasis mine.) So, right below the graphic it clearly says that macOS is merely ahead of Linux, and that Windows has more than 50% market share. This is from a Mac perspective; which is why a Windows user could interpret it as a cumbersome way of saying, “Windows is still number one.”
This graphic is not perfect, but it’s not misleading, and certainly not a lie.