Yes all my arguments apply to my hypothetical codec. Where did I imply otherwise?

If you want your codec to be adopted despite lack of hardware/software support, you really need to offer something worth the hassle. Notably reduced buffering wait times for consumers, and lower bandwidth costs and ease of distribution (encoder/decoder) for pirates would be such needs worth the hassle. WebM is worse in all these cases. Very few people care about royalties, so it's simply not enough to ask everyone to swap out all the hardware and other infrastructure for mostly ideological fluff.

You actually need to make a better codec. And so far there is nothing out there (H265 and VP9 don't have a usable encoder/decoder).