i know some people who believe that moving the axle all the way back like that actually improves handling somehow.
yes, on some tracks, given some bike setups .. in theory it makes for a more stable bike. but we are not talking highway speed setups. we are talking 4th-5th gear, 14,000rpm sweeping corners with both wheels sliding a bit. having the wheel all the way back MAY have it not turn in as well for slower corners. That said, my bikes work pretty well regardless if the axle is back or forward (gotta love the JRi shock and the cup tires).
Just because the axle is all the way forward doesn't mean the bike will turn in well, but be unstable in fast sweeping corners.. nor does having it all the way back mean it won't turn in but be stable. It's just one variable a rider and tuner can adjust when needed. Fork height, tire pressure, compression and rebound settings, preload, and even the rider position on the bike, (the list goes on) can all contribute to a bike handling well or not.
I heard talk of one pro years ago, that would show up to the track, mark the swingarm with a marker, and tell the mechanic "get the axle there with "X" gear ratio".
. they would simply have to use a combo of front and rear sprockets, and chain length, that would get the axle to that specific location.