I don't think he never saw it; hbquikcomjamesl just meant he hadn't yet seen it at the time he did the first few volumes. After all, the first book came out in January 1967, just a few months after the show premiered, so he would've had to write it before the show premiered. Much the same was the case with the earliest novel tie-ins to TNG, DS9, VGR, and ENT. They all had to be outlined, and in many cases written, before the shows premiered, so that they could be published reasonably soon after the premieres. And they ranged from debut novels like TNG: Ghost Ship -- which was based only on the writers' bible and the pilot script and is all but unrecognizable as TNG -- to DS9: The Siege -- which was based on the first five scripts and still holds up remarkably well in retrospect, aside from the retrospective continuity error of blowing up the indestructible Rio Grande. I'm not sure who would've been responsible for picking Blish to write the books; I know Fredrik Pohl edited the original Bantam Trek novels, but I'm not sure he would've been responsible for the '60s episode adaptation volumes. But anyway, it's no surprise that they would've picked a famous, successful science fiction author to do the adaptations. After all, when they commissioned the first volume, the show wasn't on the air yet and it was an unknown commodity from a producer who didn't have much of a track record. They had no idea if it would amount to anything. So they brought in a big-name SF author to do it on the theory that his name would draw in the readers.