Because the GP said "I work at Google but not on YouTube", and was speaking of Google and the sorts of technical challenges Google has in general, not any specific product.
So danShumway pointed out that in one flagship product, they didn't seem worried about latency, so it could be argued that avoiding user-agent detection is more important than latency on youtube too.
But yeah, there are lots of competing things going on, I found both comments helpful.
> Because the GP said "I work at Google but not on YouTube"
That was a disclosure, not a credential. My reading of it was that GP was speaking of the tradeoffs in their capacity as an engineer, and said they are a Googler for fair disclosure and nothing more.
They weren't explicit that they weren't talking about YouTube specifically but generally about the kinds of challenges and tradeoffs Google faces, so that's why the reply was also talking about products other than YouTube in the context of the kinds of tradeoffs Google has been known to make. That's what it has to do with what original GP said, to answer your question directly.
Anyway, I found both original GP and the reply useful, and do not find this exchange to be, so I'll stop!
So danShumway pointed out that in one flagship product, they didn't seem worried about latency, so it could be argued that avoiding user-agent detection is more important than latency on youtube too.
But yeah, there are lots of competing things going on, I found both comments helpful.