Amsterdam may not be the best existing public transit (+cycling friendly), but it is the most visited city in the NL - and it is good enough at it - that it is understandable how it becomes the standard for how a (large) city can be decent to non-drivers

I myself have never been to any other places in the NL and use Amsterdam as an anecdotal example of how things can be good

(Also of how bikes with peda- instead of handgrip-breakes designed for tall people are tricky for us shorter folk)

I imagine more people who've traveled, and are not from the Netherlands, are likely to have been to Amsterdam than to Maastricht, meaning it's easier to index on how Amsterdam functions than Maastricht for discussion.