Ultimately, it is what it is. Some feel that such...adherence...is what preserves the intangible appeal of the site, others disagree, but the only part of that that matters is that the people making the rules have made it as such. Clearly, it's felt that these rules help take APUG from "the best option" to "a great option", regardless of what alternatives may be out there.
As far as alternative processes, it's important to keep in mind that there are two very different rationales at play here: that of a reasonable alternative in the real world that is on par (economically, conveniently, etc.) with digital conversion, and that of an approach that complies to an arbitrary guideline (please don't read a negative connotation into that). In this case, unfortunately, the two appear to be somewhat mutually exclusive.
Is the current situation perfect and without flaw? No, but all things considered, I think the staff does a great job handling the situation as it were. For me personally, I use APUG to post, communicate, and learn via text. It's a bit of an ironic condition, considering the subject matter, but when I signed up, I read the guidelines, and in checking the box, agreed to abide by them. For my own approach, the guidelines for posting images here conflict with what I feel is the best presentation for my photos, so I made the decision as I signed up that having a gallery here simply wasn't going to happen, and I've moved past that.
Would I absolutely love to have a gallery here? Sure. Would I become a subscriber to do it? Possibly...probably. Would I do all this just to show raw scans that have not gone through my own workflow, which I don't feel are representative of what I'm doing? Absolutely not. So in this case, I'm grateful for what I have in participating on the forum, and understand that that's the extent of my participation. If, in the future, APUG became a pay-to-post site, or a pay-to-view forum, I'd revisit the question...though with the same restrictions placed on galleries, I'd likely not pay.
I understand the rationale behind the rule, but it simply conflicts with my own philosophy on the subject. Luckily that's not a deal-breaker for this aspect of the site.