I think you will find the individuals who post regularly to the "FIRE and Money" forum are generally self-selected invest-it-yourself tinkerers. Most of us are constantly studying and talking about improving our investing, because we enjoy doing so. We almost all save a lot on portfolio management fees, and we almost all make investing much more complex than it needs to be.
Imagine a forum for people who rebuild old cars in their garages, to which you post the question: "Should I go to the dealer or to Jiffy Lube to have the oil changed in my brand new car?" Most of the responses would probably be: "Well, I would just change it myself, but I send my MIL/daughter/cousin to ____."
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If pressed, I might even admit that the simple portfolio I describe has a good chance of beating my actual portfolio's performance, and would definitely be less volatile than my actual portfolio. However, I expect to continue tinkering.