How so? HR needs to be in the loop unless I want to take on payroll, contracts, etc. IT needs to be in the loop unless I want to spend my time setting up equipment, which certainly isn't the best use of it. I am most valuable when I am leading my team and doing engineering. Not every company is some five man outfit, and successful five man outfits have to grow up at some point. There are many things to consider when bringing someone on, even a contractor.

Some companies have trade secrets. Do you think Google is really going to let you come in and poke at the Search stack for a week just to see if you're hireable?

This isn't about the number of departments. This is about companies needing to make very real tradeoffs between maintaining their current speed/security/stability and investigating future talent.