Ultimately, in the fullness of time, the industry would ideally have a makeup that looks very much like the general population. To get there, we need to make IT seem open and friendly to individuals of all races and genders. I think, quite frankly, that should be the goal of all industries.
That said, if we are to judge the equality of hiring practices of a company, I believe we should judge the company based upon the gender/race composition of the available talent pool.
Judging a company based upon the gender/race composition of graduates will be dramatically out of step with the actual practicing talent pool in IT for the simple reason that the practicing talent pool - especially the older, more experienced individuals - is almost exclusively white and male.
By the same token, judging a company based upon the gender/race composition of the general population is outright bonkers because the available talent pool for our industry doesn't reflect the general populiaton at all.
Should we be putting effort into encouraging more diversity in individuals entering the feild? Absolutely. Should we punish, berate or chastise companies because they can't meet an arbitrary diversity standard when the talent pool they have to select from is so dramatically universe? Absolutely not.
If we go after Twitter/Google/etc and say "you need to have a diversity in your workforce that is roughly equal to the general population" or, worse, "you need to have a diversity in which all races are represented equally" we are crippling those companies. We are basically telling them "you must select only from amongst the youngest, most experienced graduated, and you must throw out white male applications, even if they are massively more qualified."
That has two very nasty effects. First, it dramatically depresses wages for white males, as they become persona non grata that only very small companies or those who flat out don't care about their public image will hire.
Second, it means a lot of very talented individuals who just happen to be white males can never contribute to the "big boys" because of the colour of their skin or because they posses a penis. This means that those smaller companies which pay less for their talent potentially get top quality labour, enough to drive the big guys out of business. This results in fewer jobs available for everyone, but also kills off the companies that were deeply invested in what I can only term "irrationally disproportionate false equality."
Unless there are a much higher % of really smart, talented people amongst non white males, the above seem inevitable to me. Mediocrity is okay under radically disproportionate false equality because the demand for bodies amongst a tiny potential pool of individuals will vastly outstrip any natural excellence-based selection pressures.
So what then? If you turn the Finger Of Shame towards these smaller, but now incredibly successful companies that are composed of cheap "reject" white male labour do you honestly think they're going to suddenly start having bad feels about the whole thing and slit their own throats they way they just watched their competition do? Or do you think they'll say "fuck it", stick their middle finger in the air and keep the "evil" white males on staff who made them successful?
So what then happens to those minorities? They go elsewhere, seek employment...but will they now face a stigma? A question around "are you getting the job because of diversity requirements, or because you're good at it? The last place you were at imploded!"
No. I think the best path forward is to work on encouraging diversity amongst those entering the feild and to leave those employing individuals the fuck alone. They have a hard enough time finding people who excel as it is without attempting to artificially limit the pool of talent from which they should be selecting. We need to accept that IT is radically UNdiverse as an industry, and that it will be for decades to come.
We shouldn't be punishing people for this. Using the stick is going to help noone. But careful application of the carrot will solve the problem in due time.