Not in the European graphic arts market Mike, or, at least in part, the US graphics market. All cut and paste I have ever done (umpteen years as a technical rep with the 'Big Yellow Box'), and seen done, used a Swann Morton scalpel. Every graphics materials supplier in the UK, and certainly northern Europe, stocked and sold thousands of them.
However, I have seen the X-Acto used for cutting-down printing plates, more so in Flexography than Litho.