I'm totally in favor of having higher-ups help existing customers (I know a few companies that do this, and I like it too).
I'd even be OK with a CEO sitting in on late game sales calls/meetings, but that's a whole different issue than having a CEO make cold calls (or even having a CEO on early sales calls). It gives the impression of a one-man shop, which prospective clients will, in most cases, try to avoid.
YMMV, but with a larger operation having the CEO get involved in customer engagements that don't mean either closing a big sale or ensuring one isn't lost causes most clients to assume the CEO is their buddy.
This means he's now their go-to guy for the most trivial of issues. Besides being a PITA for the boss this also effectively neuters the account team. Not ideal.
Quality is quality, no matter how many people work at the company. Often it is preferable to do business with a one man shop versus Megacorp, because the guy/girl you are dealing with will do what it takes to keep your business.
I'd even be OK with a CEO sitting in on late game sales calls/meetings, but that's a whole different issue than having a CEO make cold calls (or even having a CEO on early sales calls). It gives the impression of a one-man shop, which prospective clients will, in most cases, try to avoid.