> it’s always easier to make an engine than a game.
It could just be different interests. The kind of person who makes a game engine is a technical optimization-focused tech-focused person, sort of like a mechanic. In order to make a game, you have to deal with softer concepts like "is this fun" which is more like a designer/artist. Game studios need to bring these people together, but in the FOSS world the mechanics are happy to spend their time building an engine that runs beautifully without concerning themselves with the art side of things.
Why assume that a game has to be made? Making a handful of tech demos doesn't come with that baggage and deflects criticism of making an empty shell of an engine with nothing to speak of.
In the real industry the very technical people are focused on very concrete problems like level 3 is causing too much overdraw on Xbox. What can we do without breaking X,Y, and Z.
Yes and no. It’s true that some people really only care about a slice of the process, but if you’ve been around the gamedev scene long enough you’ll also see people working on very technically ambitious projects while they’re fooling themselves thinking they’re making a game.
I just need a few more years working on my 4D non-euclidian voxel MMO engine before I can make my game!
In so far as comparing levels of complexity, you're correct. But that's not the salient part of the the parent comment.
A tool with a vaguely defined goals and no stakeholders is easier to make than a tool that must meet certain goals as defined by stakeholders.