Apologies, I should have been more clear as I intended to point out an example, not a fixed quota, because clearly if you consider diversity when making a hiring decision you inevitably have to end up aiming to hire more people of certain characteristics(and not necessarily qualifications) that fit your long term quota goals.
Besides, what do you mean by fair recruitment? Because personally in this context I view diversity and fairness as contradicting terms, since it would always be more fair to hire a candidate that has higher qualifications and is a good cultural fit over one that wasn't as qualified, but turned out to be a good match when it comes to meeting present quarter's diversity goals?
I believe that basing hiring decisions on physical appearance, race, religion, gender or political views is simply wrong. I recall there was a company that focused on distorting candidates' voices during phone interviews that effectively prevented the interviewers from distinguishing the interviewees' gender. If companies like Google want to actually be more "fair", perhaps they should move in that direction rather than introducing artificial quotas and justifying them with a vague "need for diversity"?