A LOT of people continue to use them because it's a PAIN to switch to a different software provider when you have used the same one for 10+ years and all your files are on that software. With 3.6, that's NOT the case, there will be appraisers leaving Al a Mode in DROVES once 3.6 is all the way in place, there's really no reason to be loyal or stick with ANY software provider once 3.6 is a reality.
You can't clone a 2.6 report into a 3.6, so what's the point of being loyal to any software company, once 3.6 is rolling, everyones 2.6 reports are almost uselss as far as GSE work is concerned, you'll just have hunderds of old appraisal reports that can't really be utilized for much.