Sun got by because they had faster and more reliable hardware than what was available in the x86 space at the time. eBay's services ran on a handful of 64 CPU Starfire servers. And proprietary UNIX workstations had a bunch of specialized apps that weren't available on Linux at that point.
That's really an old-school UNIX convention that should have died with the move from teletypes to CRT terminals. The default behavior was that ERASE was # and KILL was @ (rather than backspace and Ctrl-C). It was typical for these to get set properly on logging in.