By that logic, Apple should have been sunk in 1992, when it discontinued the still-highly-popular Apple ][ series in favor of the Mac; or in 1994, when the venerable Motorola 680xx processor was abandoned in favor of the PowerPC, orphaning users of software whose developers supported only the newer architecture from then on; or in 2002, when the last OS 9-bootable Macs rolled off the production line, leaving behind a large and often angry population of OS 9 users (*cough*grelber*cough*); or in 2006, when the switch to Intel processors put the Classic environment out to pasture; or with the introduction of Snow Leopard itself, which jettisoned the remaining PPC Mac owners in one fell swoop.
What makes you think the 1 in 5 Mac users still on Snow Leopard constitute a unique class?
