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 closely related to the infamous "Big Rewrite" problem.
> the fact remains that people on teams I've worked on have chosen libraries based on the fanciness of their webpage
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.