The problem is with the question.
Would you EVER take the shot, or would you ALWAYS take the shot are different questions.
"Are you a good enough rifleman to assess the situation quickly enough to decide?" That's a better question.
Now, for those who hunt from stands, hell, why not? You can spend your spare time memorizing the distance to every landmark from your stand to 600 yards. 300 yards with a scope and a rest isn't that big of a deal; guys who are into it shoot prairie dogs from more than twice that distance.
For those who might have a nice rock to rest on, or might have to shoot offhand on uneven, steep ground, depending on where the deer shows up, it's a very different question. Unless you think you can hold a rifle steady to 1 MOA, 300 yards is pretty far for offhand shooting, if you believe in ethical hunting, in some situations. 1 MOA for the shooter, 1 MOA for the rifle means a 6" circle at 300 yards, assuming everything else is perfect.
Like a lot of deer hunting questions, the answer is greatly influenced by conditions in someone's area.