It is harsh on the body, no question.
I don't know if "cheering" is the right word. I mean sure... there's always someone, but for most, it's the novelty of witnessing an extraordinary event.
We nick 100 F on our big heat days, with enough frequency to numb us to the significance of 1-0-0. But getting a possibility for every site to be 101 to 104? mm that is definitely novel enough to the area to take note.
It's a special anomaly ... it seems there may be an "air" ( pun hopefully annoying haha) of synergistic heat bomb about this, too. There are several factors that are likely to propel this into the "rogue wave" territory - the New England version of it, today.
One observation of note ... there was a peculiar temperature rise of 2 to 3 F at several home sites around the area, which took place at 2am, after we had settled off to 74-ish. Back up to 77... this happened well before the light rose during the bowls of deep dark night. And it continued to rise decimals per 5 minute click off through dawn. Now, 90 and 91s are common at 8:30.
This is how synergy manifests. I don't believe the models are seeing these idiosyncratic positive feed-backs...
Anyway, human curiosity takes over. There's also a ton of scientific significance to novel scenarios. But imho, I don't think the average observer of this is wantonly cheering on a injury - and if they are, they should be guided to jumping off the cliff first as their poetic justice.