Since casual users buy a device for emails, browsing the web and watching movies, they must buy a deviced adated to those needs. And the iPad v1 for instance is well suited. If you look at the iPad v1's tech specs, it is not tremendous. I don't remember exactly, something like 256MB RAM ... 16Go SSD disk .. and so on. Apple made technical choices (or design choices) based on the user needs.
At the contrary if I need to compile big c++ projects with more that 1,000,000 lines of code. I need to set-up a something suiting my needs. Either a big machine with a big horsepower. Or a compiling grid? Whatever. Something that suit my needs.