This thread reminds me of a famous quote, just wish I could remember the author and exact wording…
“Pilots record their time in the air with such detail and precision it’s as if time spent in any other pursuit simply isn’t worth noting.”
Whoever said it, it’s true. 
If the time counts towards any kind of achievement, why not just block dev mode time from counting towards that, but keep all the other logging data? I find it kind of strange that it doesn’t even log the three most recently visited airports in dev mode. That would be handy now and then.
If there’s an achievement for tabbing out to 3DS Max and completely forgetting that FS is running in the background for 2 hours, with 37 airplanes piled up on the taxiway behind me… I should have that one 20x over by now. They could call it the “Hey dude, the light’s green now you know.” achievement.