1) STEM isn't a thing: Chemistry is real. Calculus is real. Computer Science is real. All of these are difficult, important, and perhaps lucrative subjects that many do and some should study in school. STEM, on the other hand, is an odd bundling of these disciplines designed to promote "Spaces-to-Make" and "Code for 3600 Seconds" and "Paperweight creation engines". These disciplines are already very real, very important, and frankly, very difficult. And hardly cool. Chocolate-covered broccoli isn't fooling anyone.
2) We Need More Girls In STEM Because?: I realize I need to tread carefully on this topic because it could be taken the wrong way, but I've never gotten the argument that we need more girls in "STEM" (or that we, conversely, we need more boys in liberal arts). I don't think any sane person would argue for less girls in "STEM", but the need for more girls in STEM "because there currently aren't as many girls in "STEM" as boys" seems like a circular argument. If you're arguing that girls fall victim to social pressure to value their appearance over their academics (as the keynote speaker stated), that's one thing (and definitely something that should be changed) but that doesn't really have anything to do with science and math. If more girls pursued "STEM" that'd be great. If they don't, that's fine too. Every single subject out there has a majority of a certain group (age, race, gender, income) and perhaps...that's ok. If science and math has been discriminatory in the past, obviously that's a problem, but if it's simply a lack of interest, maybe it's ok to "let students follow their passions" rather than selling them a new acronym.
3). If STEM were important...it would be important: My favorite line from The Social Network is when fictional-Mark Zuckerberg confronts his adversaries in court. They accuse of him stealing Facebook from them when it was, originally, their idea. Mark looks at them and says "If you guys had invented Facebook...you would have invented Facebook." In other words, sometimes if you have to say something out loud, it's probably not the case. It's the same trap I've seen every discipline fall into; if you have to make a big scene about how important your subject is...it actually must not be very important. No one questions "hmm, is history actually a subject we need?" in school, and no one says "how important could English really be?" The just...are. In fact, no one questions the value of math and science either! You'd be hard pressed to find a reasonable person that wants to cut them. And yet "STEM" is loud and proud about how great it is...which is code for the fact that it's probably not that great. Why else which such a heavy ad blitz be needed to put it front and center in conferences and districts across the country?
Science, Technology, Engineering, and Mathematics are all excellent and valuable subjects. They're also completely different from whatever "STEM" is. "STEM" is a marketing term, just like "New Math", and "New Coke", "Zero Trans Fats", "No Initiation Fee", and "Gluten Free". Someone is making a lot of money from all the free advertising being done on its behalf at these paid conferences. Sadly, those someones aren't the students.