Saw this photo posted on another site:
View attachment 40231
Philbert
I'll add a bunch of aggravators tomorrow
but the main reason by far is you are creating a catapult without defense.
The thing about falling, it's a system that has safe procedures that back each other up. Example: Work from the high side, clean out the cuts as well level and precise cuts, do a site overviews, look up frequently, leave an anti kickback step, cut saftey trail, clean saftey trail, walk saftey trail (two on a danger tree), degress 10 ft from stump, no brushing of standing timber ect. There is multiple steps in place and sometimes we need to miss CERTAIN ONES or maybe two steps to overcome a falling difficulty which increaces the risk to do on a regular basis. Now sometimes chit happens like cutting off your holding wood and losing a tree over backwords or sideways . A tree always starts to fall slow in most cases, even a tree that you just lost control of is going to stay on the sump for a period of time and you have time to see the direction it's committing to as you make your exit plan. In this case, well as the case of a hinged tree,, revert to Newtons first law of motion.
"What starts in motion will remain in motion until it comes in contact with another body" (speaking of which, that is what a kickback step if for on a hinged tree. A lot of things are in place for the "What if".)
In the case shown in the picture; Refrence:
Newtons third law, as follows:
"When one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction on the first body.
This is creating an equal and opossite reaction. This will launch the butt off the stump in possibly a forward direction very quickly without the security of a "safe" (high) side. Very very dangerous.
I hope this answers your question a bit better.