I've observed that Group 2 (your 75%) frequently winds up in "Director of IT" positions where they can productively re-use that year over and over again keeping the ship running. Some of it is a lack of imagination, some just a simple desire for stability. Either way, they get very stuck. Their firms can't afford for them to do anything else, and they have to take a pay cut if anything bad happens.
Now my question.... By keeping a low profile, do you feel you are artificially lower your wages or opportunities? You're in the same boat as the top 3 or 4 developers I know - very talented, well paid, jobs find them, and employable in any market. But sometimes I wonder if they could get paid more if they were more visible, simply from supply/demand. (They have a scarce skill, increasing the demand for it should increase the wages) Or is it that anyone who would properly employ them is by definition outside mainstream hiring and would know them already?