For one thing, facilitating spam is some distance further down on the benefits to harms scale than facilitating Facebook or Google. Google, especially, has created a enormous amount of value, and continues to do so^; spam, not so much.
^Which isn't to say that it's perfect, of course. Or even necessarily a net good, although my personal belief in the case of Google is that it still is.
Is an arms manufacturer at fault when there's war?
China is always going to censor. Google facilitating it or not make no difference. Might as well make the money, and also hope to influence the system from a position of power rather than a position of weakness (i.e, not involved at all)
That's like saying theft will always exist, so you might as well go steal things. Tools like this actively add to the quantity of spam out there, making it worse for everyone.
Although this spamblaster is terrible, I consider Instagram to be a clear net negative for humanity. It has almost no redeeming traits, it just makes people insecure, envious and wastes their time.
I can tell you it's a net positive in my life. I rarely use facebook proper, but I quite enjoy instagram. I keep it to a small number of actual friends (I think I have about 20 contacts, or whatever they're called on Instagram.) And I enjoy opening it and seeing what they're up to once or twice a day.
I think you and I are the very, VERY small minority. I muted everyone I didn't care about too, and it works for me, but young people especially are very affected by it.
^Which isn't to say that it's perfect, of course. Or even necessarily a net good, although my personal belief in the case of Google is that it still is.