If a company isn't going to use a framework, they had better architect and spec out their app with heavy documentation. I would argue this is more for the stability and future of the app and company than it is for ease of hiring purposes.
Without a spec or framework, you run the risk of ending up with various styles of code (often times some really terrible stuff) sprinkled throughout the codebase, constant arguments between devs (as there is no established standard within the code) and a mountain of "tech debt".
That's only relevent when you are hiring someone to deal with the monstrosity of a rails app that you ended up with because the abstractions didn't quite work for the problem you were trying to solve.
I've found it very easy to use some Rails best practices in a Sinatra app and not have to deal with all the routing/controller cruft in Rails, while still getting sensible filesystem conventions.