Why not lock it in first???

Yesterday night, i was looking in my revo too see what i could upgrade on it, and start to think about the tranny gears. Why peaople don't let it in first gear and adjust the pinion/spur to have the desired top speed????
just tighten down the adjustment screw to avoid the tranny to shift in second
It's a easily way than lock it in second.
For exemple, on my revo, i've the wide ratio, 4s li-po, and 38 spur, if i let it in first, with a 22T pinion, i hit easily 35m/h, it's a reasonable speed for the track

Need your comments, and BriandG comment is welcome!