That's why I've always thought the "literature of ideas" tag is simply a justification for bad writing. Anyone can write ideas; the trick is to write compelling characters. For example, take the Ghost in the Shell: Stand Alone Complex series that I just finished watching; the same ideas exist in the manga and anime, but the characters in the anime, unlike the manga are well-developed enough that they carry the story and make it interesting.

It's interesting that a couple of my other favorite classic authors Schmitz in particular. is very good at characterization. In Witches of Karres for example, while the witches may have the cool powers, the hapless captain's reactions are what carry the book.

I also was was also going to bring up classic plots (especially exploration and finding one's own place, or getting acceptance), so I'm glad to see you brought it up.

I really do need to read more Simak; I read the bittersweet Way Station at a vulnerable point in my life, and so I've been a bit wary of him since.