There's some good info in there.
Some are actually kind of humorous.
Some of them contradict each other, and some contradict themselves, and some of them make big assumptions.
Some of them are just flat wrong.
They are opinions, and opinions vary. This is why a good trainer will say "This is a way, not the way." These are examples of why and also why that idea should be in the mind of the reader even when the writer isn't actually saying it. Maybe especially because the writer isn't saying it.
Don't get me wrong, there are some very good points in there. You just need to figure out where they are and what is dogma. See what fits your needs, pull that out, and use it.
I've got no problem with simplicity, and I think that if you are building a defensive gun you absolutely should not have something on there for cosmetic or psychological purposes. If an item does not add or increase a capability it should not be on there. If it does so but at a significant cost, it should not be there. At the same time, minimalism simply for minimalism's sake can be counterproductive. Some people take it to a religious level and in effect want to pillory anybody who doesn't worship at that altar.
On the other hand are the people that get what they describe as an HD gun and put 6 feet of rails on a shotgun and then get every possible thing to hang off of it on there. Then they post a "Critique my build" thread and get butt-hurt when they are told why their stuff isn't well-suited for a defensive gun. Asking about it beforehand is one thing, justifying it after the fact is something else. To clarify, Rip you did it right. Plan it out, ask for input, try it out, then decide what you actually want and need on there.
What's really entertaining is seeing people like that show up for a class. You don't want to be "That Guy."