Yes, seriously. Why make the job more difficult?
If an intercept causes TCAS RAs, then the interceptor must deal with the resulting the escape maneuvers.
A military intercept a few years ago caused the target (a civilian ATR72 full of passengers) to perform numerous successive TCAS RA escape procedures for nearly 20 minutes!!
The ATR72 crew thought they were in imminent collision and the passengers must have been out of their minds!
Not only this encounter endangered flight safety, but surely it would have been better for the interceptor to simply have turned off his Mode C per procedure, and avoided all the extra work of chasing the plane for 20 minutes.
And I'm sure his commanders weren't too pleased to deal with the ensuing bad press and media circus!