Okay, "ripping off" isn't really the right phrase - he just happens to have the same style of writing and similar themes. They both take a protagonist's mindset from their time, and then drop it in the world of tomorrow. In Heinlein you have a kid going to the local soda fountain to get advice on how to tinker with his space suit, and in Doctorow it's how to tinker with your social network.
I happen to love this style of science fiction, because in general I feel one of the main messages of sci-fi is that while technology and environment may change, humanity's biggest challenge will always remain coping with it's own nature. So it doesn't matter whether you're on an alien planet or on a server farm in orbit, it all boils down to what does the individual do when faced with a problem.
And I like that, in both Heinlein and Doctorow, the problems are both fantastical (aliens, killer cyborgs, virulent plague) and beuraucratic.
Death and taxes.
Anyway, one of my favorite science fiction books of all time is "Have Spacesuit, Will Travel," by Robert Heinlein. The title is a play on the title of an old Western television series from the 1950's called "Have Gun, Will Travel" about a wandering, hired gunfighter named Paladin who tried to solve problems without using violence (this never worked, of course).
The book has little to do with the television series, except for the sense of high adventure and the idea of trying to solve problems with one's wits rather than brawn. It's the story of a young boy who is trying desperately to get to the moon, and then ends up going there and beyond. Simple and fun and good for most all ages.