TBH, I really don't think that Spyderco would get a return on their investment if they did it. I've had an SAK in my pocket starting in the late '70s, and IMO Victorinox are the absolute masters at it. Not to mention that Victorinox is the largest cutlery manufacturer in Europe, and most likely the entire planet. Sal has mentioned before that Spyderco is actually a very small company, even compared to other manufacturers of 'modern' knives, like Benchmade. And Benchmade is tiny compared to Victorinox. Even if Spyderco could put harder steel on a multi-tool's knife blades, the cost of such an item would be prohibitive. A multi-tool by Spyderco with comparable features of a standard 2 or 3-layer SAK that can be had for around $30 or less would probably cost at least 3 times as much, and would not get the same exposure at big-box stores that Victorinox does.
Jim