>Does the lack of serious competition against Photoshop keep Adobe from re-thinking the interface?
It's probably more a case of pros who have invested a great deal of time in adapting themselves to Photoshop's workflow and quirks would be really upset if they rethought the interface--however excellent a job they did.
FWIW, Adobe did a really excellent job when they had a clean sheet of paper with Lightroom, although it took a couple iterations to get there. (Mostly--it's more modal than I'd prefer in some respects.)
It's probably more a case of pros who have invested a great deal of time in adapting themselves to Photoshop's workflow and quirks would be really upset if they rethought the interface--however excellent a job they did.
FWIW, Adobe did a really excellent job when they had a clean sheet of paper with Lightroom, although it took a couple iterations to get there. (Mostly--it's more modal than I'd prefer in some respects.)