I think the eggs you see Yoshis lay aren't really eggs, they're funny looking feces. I don't think we ever see a Yoshi lay an egg that later hatches into a Yoshi, we only see Yoshis lay eggs
It's funny you say this because I have similar thoughts on Birdo's eggs. No game has ever shown anything hatch out of a Birdo egg, so they are probably more like some kind of excrement.
To continue this poor thread's derailment: the male seahorse doesn't lay eggs; the female does, but the male inseminates and carries the eggs within a pouch in its body.
I didn't say the male produced the eggs, I said it "laid" them, which that could still qualify as. The same process could hold true for the Birdo species as well. Or maybe Birdo found some other creature's eggs somewhere, devoured the lot of them, and is regurgitating them? Anything's possible.
And about the actual thread: I wonder if a better title might be "Are Nintendo's fans losing touch with Nintendo's roots?"
To this I myself believe that the answer is "yes".