I believe a counter argument to your statement would be - there can be considerable resources stored in that trunk segment, especially in the spring after the roots have started pushing stored nutrients upward. I had a box elder tree cut down last summer, and they left behind some substantial pieces of trunk for our use. These logs (about a foot thick, a foot or so long) sat out all winter and a couple of them are actually pushing out growth this spring.
My personal feeling - when you collect a tree, you lose a lot of feeder roots, sometimes almost all of them. What builds roots? Foliage. So having a little extra trunk with a little extra stored energy may give new shoots and leaves an extra boost, which in turn could help recover the root system more quickly.
Or maybe not...
Chris, very valid point. But I believe stored energy is there inch by inch. What you have left proportionately have same stored energy. Stored energy however is finite...it need to be replenished eventually. Which does that? The root and leaves, the more you have to replenish later taxes the plant more IMHO.
My analogy is a household with great income and savings (the healthy tree)... then it lost income and have to live with their savings (tree got dug up, have to use stored energy). The smaller the family, the longer the household can stay afloat given their savings (shorter trunk). Bigger house cost more, use more utilities, etc. More people need more food, use more resources, etc.
Maybe I am mistaken but as I said, it works for me and will continue doing it until I find something better.
It is is not for everyone or for every tree. For example, my boxwood are kept much longer than I like just because I need foliage at the ends (or the branch/trunk/tree) will die (in my experience). Others may have unavoidable die back (again other than my azalea) I did not have this problem so I cannot relate too much...so it has to be adjusted for those. Apple however is not on the exception group IMHO.
Just sharing my style (and reasoning why) as an option...definitely not being forced to anyone.
I guess I am more passionate about this because instead of being encouraged, from the very beginning I was told by almost everyone all the following negative stuff;
You cannot do that.
Don't do that.
Shouldn't do that.
Never do that.
(about chopping hard, pinching newly collected plants, bending big branches, working on trees less than a year from collection, etc. etc.)
Well I am very happy I did because it works (for me).
To me, it all depends on the health/vigor of each particular tree (when in doubt about health don't tinker with the tree).