Earlier quoted context omitted.
https://en.wikipedia.org/wiki/Argumentum_ad_populum Has no relevance to actual language quality, potential or value. If this wasn't the case, then no language would ever pass, or fall behind, another language in popularity. Popularity is a reflection of already-realized value. That's all.
When trying to assess popularity, measuring "ad populum" is exactly the right metric (hint: look at the root of the word).
Ah, I thought he was making a different argument, my bad.
Still, "most practically used" may not equal "most used"