K-Jet provides a lots of problems, vacuum leaks, system pressure regulator etc. (I already met some, and asked in the Q&A section.) It is impossible to get new parts, or when there are some left at Bosch, they cost more than the car itself. Getting used ones is neither a solution.
That's the first reason.

Second reason is, that is cannot provide enough fuel for me, it would be more powerful with this camshaft, but it needs more fuel. And it makes faster response to any movement on the pedal

And the look: my personal opinion is, that the carbs look good with K&N's.
K-jet doesn't look good anyway...