not just mindsets, but the computing power available. These days, my smartphone is millions of times more powerful and the computation to do TLS encryption on every website I visit is trivial for a computer that fits in the palm of my hand. Way back when, the 1 or 2 kilobytes or so a modern RSA private key (PEM format) would take up on disk was meaningful when you only had 4 megabytes of RAM and CPUs ran in the megahertz range.