My original comment was about cheap bikes no one wants to steal. Realistically for mass bike use ebikes are the way and that solution doesn't work. Ebikes are targets for thieves.
Or just don't cycle on the hottest days, but only on the 'reasonable' ones.
No one says you have to do so every day.
I actually don't think the weather is even the limiting factor here in Texas. It's that it's literally unsafe to ride a bike on the vast majority of streets here under fear of serious injury or death.
People bike in any kind of environment and terrain, it's up to you to understand that ultimate convenience is not the bike's proposal, it's a simple, reliable, and fun tool to use to transport oneself when walking would take too long.
I live in a hilly place, with freezing winters (Stockholm), and I bike every single day of the year. I need 2 bikes for that: one for when it's not frozen outside and another that can take me safely on frozen/snowy ground. That's it.
When I lived in Brazil I also used to bike, in 30-40C, on a very hilly city (São Paulo) that was absolutely not made for cycling, we barely had bike lanes at that time in the city, it was still doable when distances were anywhere between 2-15km.
So yes, it's not the ultimate convenience as sitting inside your own personal refrigerated metal box but it's absolutely doable.
So yeah any starry eyed biking idealism dies in Texas.
I also lived in Sweden (Malmö) and it was fantastic for biking. Sweden is extremely spoiled for biking infrastructure, however. In Malmö you get dedicated bike paths that are separated from the road in a raised manner (eg above the curb) and also from pedestrians. The biking infrastructure in Sweden is probably second only to the Netherlands or Denmark in that regard. And the gap between what these countries offer and what something like the USA or Brazil offers is just massive, as you almost certainly already know.
I agree that most weather situations are pretty tolerable for biking. But there are some extreme temperatures (40C, -20C) that are not conducive to biking. As long as where you live doesn’t have that as a decent chunk of a season you’re fine to use it as a commuting tool, all other things considered. The problem is really rather whether getting on the road makes you actually legitimately in a statistically founded fear for your life, as is the case in Texas.