This is a pretty strong statement, and I believe that it doesn't help in anyway in the already problematic IT hiring practices and bias against older professionals.
There is absolutely nothing wrong about staying for long in the same place in IT. Not everyone is interested in progressing their careers at the same pace, and there are many variables that should be considered before judging someone career choices, i.e. work-life balance, family or simply liking the place where you work.
I believe you had good intentions (as you article points, you wanna help people progress in their careers), but putting it like that sounds blunt and does not help much.