Earlier quoted context omitted.
There is selection bias there, problems that do get settled stop being dragged on.
Yes. A lot of this discussion hasn't grasped your point. Philosophy did settle a lot of questions. They became natural history, physics, chemistry, even mathematics. The ones that are taught in Philosophy courses are the ones that haven't been settled.
Anyway the main point of that quote is that without developing a consensus or the ability to experimentally test theories, debates have a tendency to drag on for centuries without going anywhere. Of course philosophy can't settle issues experimentally.
The main criticism I've heard of philosophy, is that they don't try to form consensus and encourage the dragging on. Philosophy students spend their time reading through the history of philosophy and studying old arguments and issues. Whereas in math or science, there isn't really an emphasis on history or even that much about ongoing debates.
Mathematicians don't have a way to experimentally test ideas either. Certain ideas, like the validity of infinite sets, or of Cantor's diagonal theorem, are arguably philosophical in nature as much as mathematical. And were extremely controversial at one time, with many notable mathematicians taking the side against them. But mathematicians did come to consensus on them, eventually.