For a society to function there needs to be balance. ‘You can do whatever you want as long as enough people pay you to cover your bills’ gets bleak fast.
It's a net benefit for society, even if you don't personally like it.
There are fewer viruses on Linux than on Windows, despite being far more open. I imagine your response will be that there are a lot more iPhone users than Linux ones, but my point is that there are a lot more factors than treating "open or closed" as a binary, and at best you can make a principled hypothesis about why something doesn't exist. For all you know, maybe making it more open would allow security researchers to find and report more potential attack vectors; extra attention from being more widely used cuts both ways.