Well, since you're asking me, I will answer you directly. More than that, I will answer you with a level of truth that you are unlikely to ever hear from somebody who has gone as far in school as I have.
A PhD is meaningless.
The only thing a PhD says about the recipient is that they were able to do the following:
1. Complete more coursework
2. Conceptualize a research project
3. Pass preliminary exams which test their knowledge of subject material and demonstrate they have the ability to carry out a research project
4. Complete a review of relevant literature of their topic area and write up those results
5. Collect data; analyze that data; interpret the results of the analysis; write up those results
6. Defend, orally, in front of a committee of learned professionals, the entirety of the research project
That's IT. The PhD says NOTHING about the ability of the recipient other than to say that person was able to endure more coursework and could oversee a research project. No expertise is needed whatsoever. Unfortunately, academia likes to portray people with PhDs as some sort of subject matter experts, and most of the time, that is not the case at all.
Now, for the other point you made. If I am knowledgeable about things, it is because I have read about them. My knowledge about most things in this world goes no further than the text books I have read. I have very little first-hand experience with most things in life, so my "knowledge" of a particular topic is mostly purely academic, and all I can do is parrot what other people have said. The only really "sad" part of the whole thing is - I'm generally not interested in getting first hand experience with most things. Reading about them is sufficient for me. Most of my life experiences have been major disappointments or have been rather catastrophic, so I prefer to live vicariously through the descriptions of events by an author.
