It was a foolish choice of balance point since almost nobody has eight encounters a day (even including skill challenges). It certainly happens sometimes, but you can sit and watch any FLGS table, any youtube D&D stream, or study the natural pacing of any official module... and a full eight encounters is rare as hell.Because the design balance point doesn't change regardless if many DMs ignore it.
But I completely agree with you that 13th Age uses a great system, and have started using it myself.