You're missing hte point.
a) Google was deliberately allowing dodgy companies to advertise -- potentially exposing us all to scams and malware.
b) Google banned some legitimate companies from advertising with it because it felt like it.
Now, if point 'b' above is correct then, as you quite rightly point out, "it's just business" -- though for a company which says "don't do evil" it seems a little odd, I also wonder at a company whose T's and C's include "we can drop you any time for no reason, ner ner" when they're all for neutrality and all that.
If point 'a' is correct, then Google have deliberately exposed a large number of web users to problems for their own financial gain -- which seems a little "evil" to me.
Google are generally "bashed" for being hypocritical rather than for being a business -- and a lot of their practices make Microsoft and Apple look downright "caring".