> Of course, but one should be aware of a tendency to overestimate the effort required for tweaking third party code (understanding somebody else's code is always more difficult), and underestimate the effort required for writing the thing from scratch.

It's not just the cost of tweaking, it's the cost of keeping it up-to-date, too. I agree with the general gist of what you're saying, just wanted to point out there's more to it.

> I believe you, but I find it difficult to believe these would be the same people who tend to introspect on their profession a lot, eg. by following software engineering blogs, so the author is kind of preaching to the choir in my view.

On the contrary, I think people who don't introspect about what they're doing are more likely to read tech blogs. How else would they find out what the latest fad libraries are so they can treat them as best practices? :)