Why didn't transcripts of Postcard survive? The conceit of COAP is that the image files were lost, but transcripts like those of SROMG would have been useful for producing a fan-made remake like Sonichu got, or even an official remake like a few comics with heavy Art Evolution get, possibly based on the one strip that did survive.
Because that's not as funny. You realize that Postcard`s missing image files are completely intentional, right? The whole point of the comic is that the "author's commentary" is all there is, and any actual content that the comic might have had is left to the reader's imagination. And that one strip that did "survive" was published on April Fool's Day.
Speaking as one of the very few who was involved with the April Fool's strip, it's nice to know that somebody got the point. :-)