That's extremely unfair to whoever's chosen - essentially, they're being shoved onstage not because of their particular talent, drive, or accomplishments; instead, they're just defined by their genitalia because of some arbitrary quota. The intention may be nice, sure, but the message such it sends is a huge slap in the face.
Plus, putting writers/marketers/etc. onstage for tech demos? Yeah, that's going to be pretty obvious. Even with producers/designers/etc., you're putting people without serious training or experience in public speaking in front of millions. That doesn't sound like a great plan. Hell, even the presenters with experience were often awkward and shifting. You can't quite just throw someone on stage and expect magic to happen.
As I said before, the games industry is heavily weighted towards males.
According to Forbes, at least 88% of its employers are male - and I guarantee you that ratio only gets more and more skewed as you go up the corporate ladder. Sony probably wanted to use big, respectable names (or, at least, higher-ups from big, respectable developers) to lend credibility to the product they were selling. The sad fact is, you're more likely to find Waldo in a random crowd than a woman who fits that categorization.
I'm glad people are noticing this, but to lay the blame at Sony's feet (
especially when they've been using scholarships to encourage women to enter the industry for years now) is to miss the bigger picture. It's not a Sony problem, it's an industry problem, and it's not a problem that will be remedied until we begin addressing it as such.