I read the thread on removing the stem, and in discussing the topic of perfection in drilling I think it's important to separate straight and bent pipes. It will be obvious to some, but I have encountered pipe smokers who regard as poor craftsmanship what most pipe makers regard as unavoidable compromise in order to achieve design objectives. In order to get that lovely S-curve in the shank/stem that many of us like, there are two options -- either adopt a curved drilling (which has its own problems) or, as the vast majority of makers do, use straight drills but create an angle between the mortise and the airhole. The more bent the pipe, the greater that angle must be. For a given bend, more angle in the mortise/airway permits an entrance of the airhole into the bowl closer to 90 degrees.
So, is a bent pipe with an airhole drilling that enters high in the mortise end and is ramped down so that a pipe cleaner will pass imperfect? Some would say yes, but those people will be constrained to purchase pipes that are either not very bent, are drilled with a curved drill, employ an abnormally short or large tenon, or are drilled through the mortise face. A deep bend done with straight drills may require a combination of adjustments, including a forward-canted bowl.
I would say no. Bent pipes are popular, and each maker must judge for himself the market resistance to the various drilling solutions. I think more people are bugged by a deep groove drilled through the mortise face than by a carefully ramped airway, but that's just me. I don't find that a ramped airway, cleanly done and matched to a funneled tenon, has a negative effect on the smoking quality of a pipe, but, again, that's just me.
A straight billiard with a ramped airhole, that's a different story. A bent pipe with an airhole off center in the mortise left or right, also.