Often a hard dev interview process is designed to week out undesirable employees, like ones who will demand vacation, time off, normal working hours, etc. I interviewed at a software place in a big engineering college town and their interview was built like a college exam and asked questions that senior-level students would know, but you'd have forgotten within a few years because you'd never use that information in the real world. It was obvious they wanted to hire people who are used to sleeping in dorms/libraries/desks, used to staying up all night, motivated by an authority figure telling them something is important, people who didn't have families or high expectation on salaries. You know: college students.

It's a hard interview for us because it's built like a college exam, and how many years has it been since we've taken a college exam? But their target audience, well they just finished midterms.

That's not a hard interview process, it's a targeted interview process designed to accept reasonably intelegent and 'incompetent' people. Which is really how most large consulting firms operate.