He covers a lot of ground in that article, so there are a lot of nits to pick...
But Tolkien's orcs don't have babies.
Actually, this is incorrect:
No female orcs are ever mentioned by Tolkien, but in The Silmarillion, he wrote that "the Orcs had life and multiplied after the manner of the Children of 'Illuvatar';
As for the larger question of "is it okay to kill orc babies?",
surely that must be a campaign-specific decision? If I'm playing LotR, the answer would seem* to be 'yes'. If I'm playing Eberron, it's a fairly emphatic 'no'.
* Although, actually, even that is debateable - if the orcs were created by corrupting elves, what exactly is to say that they can't be un-corrupted with time and effort?
That's not fantasy, frankly, at least not in its classic sense. That's the sciences of anthropology and psychology.
Again, this is not so much fantasy as it is paleontology and evolutionary biology.
I have a real problem with being told such-and-such "isn't fantasy". That smacks of One True Wayism - it may not be
your fantasy, but it might well be
mine.
(And that's something I really hoped WotC had learned from the controversy over the 4e DMG, and it's advice that particular types of encounters "weren't fun" - the underlying advice was actually good, but it got swamped by the controversy due to the authoritarian tone.)
Besides, it's a bit of a stretch declaring these things "not fantasy" because they're instead "the sciences of anthropology, psychology, paleontology, and evolutionary biology." Honestly, that's "akin to calling an angel 'simian' because it resembles an ape in its general shape."
Again, I think this is something that WotC would frankly do well to stay clear of - some groups will want a pseudo-science explanation for dragons, and orcs, and so forth; some will want pure fantasy. Unless WotC
must answer that question, they probably
shouldn't - provide support for groups who want to take both approaches, while favouring neither.
Dragonborn have draconic origin, but their bodies look basically human in shape, including the distinctive curves of the female human form. Why? Do they nurse their young? Of course not, one argument goes—they're reptiles.
Blimey. First Orc Babies, and now Dragonboobs. He's really gunning for those controversies, isn't he?
Personally, I think dragonboobs are pretty stupid (though a bit less stupid than boobs on the female Shardminds, but never mind). I would much rather they had differentiated male and female Dragonborn by giving the former a head-crest or similar marking.
But, honestly, I don't mind that much. WotC decided to go the other way, and that's fair enough. Given that Dragonborn are highly unlikely to feature in any game I run anyway, it's just not worth getting too vexed about.
What does a cosmopolitan city in the D&D multiverse look like? Let's set aside a planar metropolis like Sigil for the moment and consider a place like Waterdeep.
The problem is that not all such cities are created equally. Greyhawk City isn't Palanthas, which isn't Waterdeep, which isn't Tyr, which isn't Sharn. I'd expect Palanthas to be much less diverse than the rest, due to the rather more insular nature of the Dragonlance races, while it's pretty well established that Sharn is much more diverse.
And that actually pretty well illustrates my big issue with this article: he's ruminating on the "right answer" for the D&D cosmology, but the truth is that even amongst WotC's own published settings there
is no single "right answer" - what works for Eberron won't work for Dragonlance (and vice verse). When you expand the same out to include the thousands of homebrew settings out there, the problem only becomes greater. If WotC fix on an answer and tell us "this is how it is" then they're producing materials of limited utility.
If 5e is an attempt to reunify the fan base, they need to pitch a big tent, and not just in the rules.