Yes, not a good look from plotty and SaaS in general.
Yes it's a nice illustration why you should not use a SaaS like plotly, especially considering that there are many options out there which could have put the plot into the post directly.
At the very least it's a nice illustration of why you can use plotly but just take a screenshot and post that.
I hate to defend plotly, because this is awful. But you can also embed interactive plotly plots, rather than depending on their service.
The HN hug-of-death at work
Maybe, although since the post is from 6 years ago, it might have been hugged to death already years ago.