No, it doesn't. Sometimes you have to choose between investing a shitload of money into training someone in the platform that you have, or hiring someone who won't require as much time to ramp up. Never underestimate how much of an investment is required to train someone on a platform; what if it doesn't work out? You've just trained someone partially who can't work for you.
No one 'trained me' on Ruby on Rails as I transitioned out of working on the MS stack for the past 11 years. I learned that stuff myself.
After 4 mos using RoR on one small project, I worked to get my foot in the door for a sit down at a startup looking for their first engineering hire. They wanted someone with 3+ years experience. After seeing some of my code and doing a sample project for them (learning the basics of Sinatra/DataMapper/OAuth/FBGraphAPI to crack a problem they had a need for in a weekend), the CTO said I pretty much blew away many people he's seen who've had such experience, and in the end I was the one to say no to moving forward after the interview process.
If you're looking at people who 'need' to be trained then you're looking at the wrong people. You're looking for people who can crack the more meta-problem of actually learning shit quickly and subsequenty getting shit done quickly.
Well, all else being equal, you're going to get more out of a hire who knows how to work with the technology you're using. If I have a choice between someone who can learn quickly and someone who can learn quickly and already knows what I need him to know, I'm going to pick the latter.
