Incidentally, that’s exactly the same number as the total number of Win95 licenses sold, and I can’t recall Win95 being “too niche” for malware. Quite the opposite.
In Win95 days, "always online" was simply not a thing for the average household. Getting on the Internet - if you even had a connection at all - was equivalent to making a phone call, in that you "called in" to do the thing you wanted to do, then "hung up" when you were done (yes, I know dial-up did almost exactly that in practice, but it's still a good analogy).
Being "always online" is relatively recent, and anything online is going to be vulnerable to malware at some point in its life. Security patches need to keep up with that.