Jardine has more than a little of the proselytizer in him and, if preaching to unenlightened masses carrying massive weight, that may be quite appropriate.
Personally, I have long agreed with him on trekking poles, but I'll allow that others with weaker knees or a different walking style or perhaps just better upper body strength might like to hike with them. I don't and I'm sure I could not do as many miles in a day if I had them along. But HYOH.
I hadn't taken the umbrella plunge until 2 years ago and I like them now for some climates. I'd noted that, like people at 13,000 feet in Tevas, some of the most experienced hikers were the ones with umbrellas (goofy though they look). That, plus Jardine's proselytizing, lead me to ordering a chrome dome and I've happily used it when in intense sun at 9,000 feet or in the desert southwest.
And while he takes aim at the low-hanging fruit of heavy boots, 7-pound backpacks, and trekking poles, when I read it, I was thinking of things I still sometimes bring - a 2.5-3" bladed knife, a stove, a water filter - as things that maybe I could go without entirely or greatly scale back in weight.
50 pages of ads in each month's Outside magazine push the opposite - buy, buy, buy!, so I appreciate that one old guy with thousands of thru-hiking miles under his belt is giving an alternative message.