The only way I could really see this specific issue being addressed would be if they chopped up the dungeons and made a specific "10/20/30/40 roulette" separate from the 50/60/70 roulette. That said I always felt that the general leveling roulette was to pad out parties for those folks working their way through the entirety of the game, not just post ARR stuff so if you want that EXP then you're going to have to live with the risk that you may need to help a newbie with that first dungeon.

One thing to keep in mind is that you could be the first experience a MMO newbie has if you queue into Sastasha, so those low level dungeons can make a big impression on someone playing through for the first time.