You obviously underestimate the sverity of the situation. On 2-way maps, you used to have a minimum of 1 scout per team normally. On offense/defense maps, there was at least one on offense.
With an upgrade like the sandman, along with the other more balanced unlockables, the base amount of scouts is only going to increase. Meaning likely 2 per team minimum on a 3/4 full server, then possably more. And I have had several occasions now of ONE scout using sandman on me, then bringing me to my knees as I stare in stars in third-person, in many differnet class matchups. Heavies can survive only barely, thats if the scout is below average, or there is no other fire around, wich is almost always the case. Soldiers have it worse if they cant kill the scout immediatly, any class below that is dog meat.
Places like the vents in blackmesa, made to deter against the less combat-oriented classes like the scout have now become a target range. You can't dodge a ball very well in close quarters, meaning you are going to get a stomach full of lead before you can even start to fight back.
Don't even get me started on what it does to ubers if you stun the medic, I'm frustrated enough over the subject.
I'm not touching TF2 until a patch comes out or I find a server with a maximum of 2 scouts, no more.