The upgrade from floppy to optical only, or optical to bigger hard drives and SSDs and fast WiFi, are leaps in capability that don't even compare to the marginal gain of USB-C over USB3/Thunderbolt 2... especially when that "upgrade" is paired with the number of ports on an entry-level MBP dropping from 7 to 2 (not counting audio, which thankfully survived).
With only 2 ports, you need a ridiculous number of big dongles or hubs to get serious work done, and any pro user with >1 external HD, display, or gigabit wired is rightfully wondering what the hell Apple was thinking.