It's not only the length of the stitches, which must be close to half an inch it is also the lack of any feather/holdfast, which means the awl pokes right through the insole without the depth guidance a properly cut holdfast will give. I'm sure someone inseaming this way for 30 or more years can judge the required depth pretty good, but what about the not so experienced worker? He might go in too shallow or too deep and introduce weaknesses. If he pulls the thread too tightly, it might tear out.
Wide stitches and a thread which is not pulled as tightly as it should be, combined with a welt that lies on top of the insole (without being recessed) is a potential recipe for water seeping into the shoe. Whether or not it will happen, nobody can say until it's too late and the damage has been done.
I agree with you although that is the way it was done for many years before the holdfast as such caught on. In some circles, esp. historical circles, it is considered the correct and only way to do it. Also, I would have to look more closely but I doubt that the welt is simply laying on top of the insole. Usually, the inseaming awl emerges at the edge of the insole and often the edge of the insole itself is hammered to provide a quasi-feather into which the welt is snugged.
I won't defend it on any count. That's not the way I would do it nor do I consider it best practices. But again you need some background and perspective to know what you're looking at.
I can't imagine what you're talking about. A Goodyear welted inseam is no more entombed than a hand welted inseam. Every point at which a hand inseam would admit moisture...or not...is replicated on a gemmed shoe.
On the other hand any moisture that enters a Goodyear welted shoe is going to affect the glue. But in similar circumstances, the pitch and rosin that coats and seals a handwelted shoe...including the welt and holdfast...are impervious to the deleterious effects of water.
On edit...BTW that surface to edge technique is no less strong, if done correctly, than using a holdfast. Again, it wouldn't be the way I would do it but it is the foundational technique for all round closing and the way in which some high-end manufacturers do their forepart plug on split-toe shoes. And, by-the-by, round stitching is considered the strongest type of seam known.
Edited by DWFII - 3/8/13 at 4:32pm