The problem isn't "we are starting a new codebase with 4 engineers, are we qualified to choose the right technology?" it's "we are solving a new problem, within a massive org/codebase, that could probably be solved more directly with a different set of technologies than the existing ones the rest of the company is using. Is that worth the overhead?" and the answer is almost always no. Ie: is local optimization worth the overhead?
Local optimization is extremely tempting no matter who you are, where you are. It's always easy to reach a point of frustration and come to the line of reasoning of "I don't get why we are wasting so much time to ship this product using the 'old' stuff when we could just use 'newstuff' and get it out the door in the next week." This happens to engineers of all levels, especially in a continuous deployment, "Just Ship" culture. The point of the article is that local optimization gives you this tiny boost in the beginning for a long term cost that eventually moves the organization is a direction of shipping less. It's not that innovative technologies are bad.
> But if you know what you're doing, you choose good technologies
No, if you know what you are doing you make good organizational decisions. It matters less what technology you use than that the entire organization uses the same technology. Etsy has a great engineering team and yet the entire site is written in PHP. I don't think there is a single engineer working at Etsy who thinks PHP is the best language out there, but the decision to be made at the time was "there is a site using PHP, some Python, some Ruby etc., how do we make this easier to work on?" Of those three python and ruby are almost universally thought of as better languages than PHP, but in this case the correct decision was picking a worse technology because more of the site was written in it, the existing infrastructure supported it more completely and so as an organization and a business we could get back to shipping products more quickly by all agreeing to use PHP. Etsy certainly does not think of its engineers as monkeys, quite the opposite.