I spent 28 years working for HVAC/Sheet Metal contractors and never got over how some would routinely ignore calls from potential customers when we were swamped, not even having the courtesy of a call back to explain that we were too busy at the moment but appreciated their call. Then when things slowed down and we needed work they would cry the blues about how unfair it was that we were out of work. They never seemed to make the connection. There are folks in all trades and professions that suffer from this myopia.
As a side note I did learn to be wary of the guy who can be on your doorstep at a moment's notice when all the other guys are up to their eyeballs with work, there might just be a good reason why he's available.
That was my thought too. If the market is swamped with work and he's not busy there may be another problem.
I've called many contractors in many fields and they really run hot and cold. Some don't call back. some call back but show up. Some show up and then never come back with a quote. A few work very hard to get and keep your business.