Agree with others. I understand complexities of software dev and end users, lot's of organisations are using Internet Explorer 6 or 7 But, . . . Rosetta was completely killed off in Lion and other applications may need that.
A good example is Adobe Suites, they need Rosetta. Older versions are still more than capable of doing what people need and therefore no reason to upgrade. Recently Adobe moves over to subscription based and therefore cuts the upgrade for many devs [yes there are alternatives, even though I love the likes of GIMP it is still lacking].
After reading reviews of Lion I decided not to upgrade so no ST 3 is a big shame. I came to ST from BBedit recently and do prefer ST but upgrade path is now cut off - I've still got a license for BBedit, I'd hate to go back. Updates from BBedit still work in 10.6+
Catering for older systems is always a pain, especially when it is for the likes of Internet Explorer (even I.E. 7 is way back to 2006) but Lion only goes back to 2011. ST IMO should cater for a few years before then.
I still think ST is a fantastic product.