That isn't explanatory. If they cared about the financial investment then they wouldn't be regularly smashing their phones in the first place because it is clearly possible to do without a case. It is a side effect of behavior.

Not always. Sometimes pockets aren’t deep enough, sometimes chairs are too low so that your pockets are angled downwards. As with anything in life it’s rather foolish to think you can control everything, so you add preventative measures on top of active avoidance.

Shit happens. Putting a case on my phone improves the likelihood that my $1200 phone doesn’t shatter. People have kids, animals, and make silly little mistakes that can have massively expensive consequences.

I’m not regularly smashing my phone or especially careless with it, but in a year I’ve seen it take a dozen or so drops and I’m glad it had a case on it when it did.