Why would you boost a level 1 spell to level 2 or 3 when spells at that level already do more damage?
And even if you do so, your level 1 slot is still sitting there... what? waiting to be boosted yet again?
While your maximum damage with burning hands might be great, you aren't likely to get it. You typically get 2, maybe 3, targets IME. My post earlier directly shows how at 17th level Fire Bolt can be expected to deal more damage than Burning Hands in total.
That isn't to say there won't be times when different types of damaging spells (single target vs. spreading the damage out) will be desired, of course.
I see his point and I don't think his suggestion is crazy. It is good, but not OP. Personally, I missed the autoscaling from 1E and wish 5E had returned to it instead of "upcasting" using higher level slots. Especially when you consider the dismal number of higher level slots you will ever get!