Different, yes. "Completely awful," perhaps in your opinion, but not mine. I recognize that there are differences, but the differences are mostly trivial to me. I have a several disks with rerecorded TOS music (Varese Sarabande and Label X) that I enjoy a great deal. Not only are they well done, but in most cases, the music is not otherwise available.
If it's not original, it's not original. I'm a purist.
While I understand your feelings, my personal feelings is that such an arbitrary attitude serves nothing. I'm aware of the differences, but I choose to enjoy it anyhow.