It's not your exact words, but I don't think it's an unfair characterization, if the excuse is simply that they'll be reading it on a desktop machine anyway.
I took that image from a non-laptop desktop machine, by the way.
As another random anecdote from another random developer, I find the site's content far outshines any purported credibility loss - which just seems like a very silly argument to make.
Perf is not important for a dev resource. If a dev had spent a ton of time optimising that they'd have wasted their time. Why does wasting their time make them more credible?