Plus a healthy dose of devil worship, of course - Stephen King meets Robert Heinlein, perhaps. And, perhaps most crucially, his characterisation was very black and white - the good guys almost unpalatably good, the villains unremittingly bad . The characterisation is a lot more convincing now, but it's still not the author's greatest strength. One illustration of this is sex, of which there's rather a lot in The Reality Dysfunction . And it's not even that it makes me feel inadequate.
Sex is a complex thing.
It involves jealousies, insecurities, misunderstandings, conflicts, and more. Indeed, my biggest complaint about his writing is the overpowering compulsion he seems to have to describe everything . Every planet is given a full history, every setting described intimately. Every character is given a potted, or not so potted, history. Every time a starship opens a wormhole it's described in detail.