I don't know that I would call a Tobin a sow's ear. But, in my experience it is a design with a few limitations, none of which existed when it came on the scene.

Much metal is removed from the frame to make for the neither boxlock nor sidelock Tobin design, metal that the gun can ill afford to lose. This was most likely not an issue at the time the Tobin patent was issued, and smokeless powder loads, with higher pressure, were still over the horizon. If a Tobin had been whittled from a block of 4140 chromoly, that was then properly hardened, I also suspect one would never have a problem with one.

But, they weren't.

I have no problem with how they look, or handle, or shoot. The rollers built into the hammers, the separate, easily servicable strikers, and the springs with rollers, that do double duty as cocking rods, is a clever design. If you keep the pressure down on the loads you feed it, you can expect about the same service most other guns would give.
As the 20s began to roar, I'm guessing most Tobins had been handed down to younger shooters or served as backup guns to repeaters, and they saw more hard use, less care, and some abuse. Most lower grade double guns were not considered more than tools in that era. It isn't hard to find one in poor shape. In most cases, that isn't a guns fault.
I enjoyed all of mine, but, prefer guns that can be fed a bit more easily from the bargain table, if need be. At this time, I'm not interested in owning any of the guns that S. Bruce Ewell did in his era, for that simple reason.

Best,
Ted