Philosophy, at one point, was the catch-all phrase for any type of thought. Mathematics was philosophy. Science was philosophy. Law was philosophy. Economics was philosophy. Every form of thought (more or less) was philosophy. Over the course of history, these fields have spun off from philosophy, and achieved various degrees of relevance; their earliest works were done by "philosophers" because these fields did not yet exist, but in modern times they are studied independently. The question then becomes, in modern times, what is a person studying when they study philosophy? They are not studying any of the fields that spun off of philosophy, or else they would no longer be classified as philosophers. So, the question becomes (answering your point 5) what problems that other fields care about are still answered by philosophers? The critique in the OP correctly identifies that some philosophers still concern themselves with problems related to cognitive science, which still answer questions from psychology. But once cognitive science becomes its own independent field, there may be nothing left within the realm of philosophy.
We might not have had modern political science without Locke, Berkeley, Hume, and Hobbes. But we would have had Hobbes even if he had not been classified as a philosopher, and thus we would have had the rest of them.
We might not have had modern economics without Smith, Pareto, and Mill. But we would have had Smith even if he had not been classified as a philosopher, and thus we would have had the rest.
We might not have had modern sociology without Marx and Gramsci. But we would have had Comte even if he hadn't been classified as a philosopher, and thus we would have had the rest.
I mention these three individuals' work because they (1) fundamentally began what came to eventually be their fields, and (2) did not really build these fields incrementally out of the rest of the philosophical body of knowledge at the time. This demonstrates that it isn't some kind of unifying thread within the study of philosophy that causes these fields to spin off from them; philosophy was just what you called it when you were studying problems that weren't in their own field yet. This no longer occurs in modern times, so we don't see philosophy spinning off new fields in the way that it used to; computer science (as a whole) sees its roots in modern mathematics, not philosophy. Psychoanalysis, as a modern field (unlike psychology as a whole, which also often refers to much older studies), clearly descends from biology. Electrical engineering. Nuclear physics even has it in the title.
The study of the works of "philosophers" can still be relevant within other fields, but to study philosophy is to spend one's time looking at what's left. It is this study, in modern times, that pg and I are attacking as vague, useless, and prone to wars of semantics.
We might not have had modern political science without Locke, Berkeley, Hume, and Hobbes. But we would have had Hobbes even if he had not been classified as a philosopher, and thus we would have had the rest of them.
We might not have had modern economics without Smith, Pareto, and Mill. But we would have had Smith even if he had not been classified as a philosopher, and thus we would have had the rest.
We might not have had modern sociology without Marx and Gramsci. But we would have had Comte even if he hadn't been classified as a philosopher, and thus we would have had the rest.
I mention these three individuals' work because they (1) fundamentally began what came to eventually be their fields, and (2) did not really build these fields incrementally out of the rest of the philosophical body of knowledge at the time. This demonstrates that it isn't some kind of unifying thread within the study of philosophy that causes these fields to spin off from them; philosophy was just what you called it when you were studying problems that weren't in their own field yet. This no longer occurs in modern times, so we don't see philosophy spinning off new fields in the way that it used to; computer science (as a whole) sees its roots in modern mathematics, not philosophy. Psychoanalysis, as a modern field (unlike psychology as a whole, which also often refers to much older studies), clearly descends from biology. Electrical engineering. Nuclear physics even has it in the title.
The study of the works of "philosophers" can still be relevant within other fields, but to study philosophy is to spend one's time looking at what's left. It is this study, in modern times, that pg and I are attacking as vague, useless, and prone to wars of semantics.