It's just mind-boggling to me. The upsides seem so miniscule in comparison to the downsides of fragility and added weight. Acrylic just makes so much more sense as a material.
Related question: What high quality cases with windows are available right now which uses acrylic for their windows?
EDIT:
So the main benefits based on the discussion in this thread seem to be:
Scratch-resistance. This is unequivocally the most mentioned aspect. I've had multiple acrylic side panels and never had issues with them being noticeably scratched, but that's obviously anecdotal.
Noise reduction. Wasn't aware of this; Definitely something to consider if you're choosing between the two.
Aesthetic. This is obviously subjective but it seems like the consensus is simply that tempered glass looks better.
EDIT 2:
In case this wasn’t clear (no pun intended), I’m talking specifically about windowed side panel materials, not side panel materials in general. There’s a number of comments that seem to think I’m just talking about case windows being standard as opposed to the material of said windows.
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