I've read these before, they're great (and I'm going to read them again now for fun. :)
That said, "let’s write some classes without thinking about it!" pretty much sums up the criticism of OOP. You can't just throw your problem domain naively at some language structures and then blame the language when it doesn't work. I bet I could pick any programming paradigm and find a way to do it wronger than this.
(If I were doing an RPG of the sort in the articles, just off the top of my head, I'd probably end up with fairly abstract 'Creature', 'Item', and 'Action'/'Spell' classes, plus a big data table defining the various types of each of these and the ways they could interact. Your game designers shouldn't be worrying about compiling C++ in order to add a new type of dagger, after all!)
I'm not so sure about that. Naively the "Dog is-an Animal" inheritance hierarchy based ontology is a great match for games, but basically every beginning OO game programmer quickly finds out that it doesn't scale at all and composition is the way to go almost every time. Indeed, the currently fashionable game engine architecture patterns (data-oriented design, entity-component systems) explicitly eschew object-oriented thinking.
Actually, I spent a good 7 years in the video games industry, working everything from high level game logic to graphics programming to performance optimisation. On that last point, OOP is a complete dog when it comes to performance. If you have an update loop with a bunch of heterogeneous objects, you'll be increasing your instruction and data cache misses, by having to load vtables and method definitions. I haven't seen a situation in a game update loop where composition couldn't provide better flexibility as well as performance benefits.
What games did you work on (or kinds of games, if that's too personally identifiable), if I may ask? I'd be curious what sort of games have so many objects flying around that the overhead of vtables and cache misses was a significant factor in your overall performance.
I worked in the industry myself for a year or so, on an MMO (back when they were the Next Big Thing) and while our game wasn't super optimized, OOP overhead wasn't even on our radar as an issue compared with rendering, wrangling art assets, Scaleform UI elements, dynamic loading of the same, and all the other bits and bobs.
(Not arguing that composition isn't often better, just that performance isn't usually a significant reason why.)
