How are Cherry MX so popular? Are the just the most produced mechanical keyboards?
Most other keyswitch vendors got out of the game after the mid-1990s, when rubber domes took over the market and laptops started taking market share from desktops. Cherry managed to take most of the remaining niche mechanical keyboard market (mostly for industrial use cases, point of sale keyboards, etc.), and survive up to the present. In the last 5–10 years, mechanical keyboards have become a bit more popular again, it seems to me, and “gaming” keyboards became a big market.
As far as I can tell, Alps, SMK, Hi-Tek, Omron, Mitsumi, IBM, Honeywell, Fujitsu, Burroughs, Oki, MEI, &c. all stopped making mechanical keyboard switches sometime around 1990–1995. Cherry, Unicomp, Topre, and some Alps clones ended up as the last ones standing. (Actually, I’m not sure, does Fujitsu still do any mechanical switches today?)
There have been basically no new keyswitch designs in the last 20 years, except a few compact low-travel switches for laptops, and some minor tweaks to existing switches.