It was later revealed exactly what the purpose was, when internal mail discussions came out in court.
"What the guy is supposed to do is feel uncomfortable, and when he has bugs, suspect that the problem is dr-dos and then go out to buy ms-dos. or decide to not take the risk for the other machines he has to buy for in the office."
"What the guy is supposed to do is feel uncomfortable, and when he has bugs, suspect that the problem is dr-dos and then go out to buy ms-dos. or decide to not take the risk for the other machines he has to buy for in the office."
-- Brad Silverberg, Microsoft, 1991, as quoted at https://www.theregister.com/1999/11/05/how_ms_played_the_inc... and in many other reports of the court case that one can still find.
That was the purpose.