I think we need to ask why girls have a better attitude towards learning. Speaking as a teacher, I think that I can suggest a couple of factors and examples of why this is an important question.
TLDR: schools and schooling is overwhelmingly female oriented, and does not adapt to the needs of boys (nor anyone, really).
Schools, particularly primary (elementary for my American friends) schools are female dominated and, unfortunately, this leads to problems for boys. I taught in a school recently where I was the only male teacher at the school where there were some issues for boys. Whether there was a causative relationship or not is open to question, but the boys at the school were wild, and their achievement was substantially lower than the girls on several measures. I (simply because I was a male) was seen as the solution to an ongoing behavioural crisis among the boys in the older grades because I was seen as a role model as a boy who was interested in learning, but I think that by middle school, where I teach, it's too late for that to have much effect.
In fact, against the more influential male public role models who seem to be more interested in sport, driving, etc., than anything school-related, my effect would have been minimal (and I argued this point prior to my appointment, and my position was confirmed time after time through my appointment - in fact that failing was attributed to me which was fun). I have seen at other schools attempt to conflate an interest in sport with an interest in school by involving local sports people in reading programs at the school. The sports people come in to the school and inadvertently confirm students' beliefs, that sport and reading do not mix much. But it's a fun novelty, I suppose.
The other problem with female dominated schools is that the curriculum becomes more female dominated. At least in my experience, boys do have shorter attention spans, and do seem to have more kinaesthetic or visual approaches to learning (against girls, who more often seem to have auditory learning styles more suited to the "stand-and-deliver" lecture approach to teaching). Teaching in a single sex boys' class requires shorter lessons with more emphasis on doing stuff than discussing stuff, and this doesn't suit the approaches that a lot of teachers want to use.
Finally, there's a belief that boys are bad, whether this is explicitly stated or not, and, equally, that we should be easier on "boys being boys". In my work, I visited a school and sat through a presentation given by Year 1 students on school rules. Which was hilarious for a whole bunch of reasons, but most notably in the way that the activity seems to have been presented to the students. They were providing examples of good and bad behaviour. The teacher had chosen to tell the students to make a girl doing something good, and a boy doing something bad. The students then got up and use male pronouns for describing one scenario (where a student does something wrong) and female pronouns for describing the other (when a student does something right). The teacher corrected a student (a girl actually) twice when she said that she had drawn a girl doing something wrong, which had me on the verge of heckling the stupid woman.
As to being soft on "boys being boys", I believe strongly that we need to instil a sense of honour among boys. I had a Year 6 student a couple of years ago who incessantly physically and verbally bullied younger students and girls in the playground. I constantly brought him up on it, but was always held back from applying the school's discipline policy because "he doesn't have any great male role models", "you know his parents are really strict", or "he's just a bit energetic". The worst excuse that I heard from a colleague was that a girl he had bullied had to "share part of the blame" because she "instigated" the situation by talking to him (it's like a "she asked it by dressing that way" defence in rape cases). Over and over excuses were made for him by other staff such that he got away with things that would probably result in severe measures (like separation from other students, or meetings with parents or behavioural plans) being enacted. In fact, generally, the approach to dealing with boys at that particular school was to accomodate them rather than guide them. This meant that there were parts of the playground which were considered practically lawless by students and teachers. On the other hand, the principal strictly enforced rules for girls as petty as sock colour and the wearing of ribbons and even gave a stern talking to two Year 5 girls in my class for being best friends (because it's apparently exclusionary, even though they self-excluded themselves from other students also). I'm all for understanding students' wants and interests in our teaching, but boys sometimes do things which are stupid and they need to be pulled up for it, just as we apparently have no trouble in doing with the girls. If this is the case in regards to behavioural management, how can we expect boys to be engaged in the classroom?
It's important for me to note that I'm not saying that girls have it easy through school: they don't, particularly in later schooling, and particularly because of the social structures that we (teachers) set up in our classes and schools. But our approaches to teaching have to be modified to suit the needs of learners and I'm not convinced that we're doing it. Part of the reason is that schooling and learning is, unfortunately, seen as inherently a female pursuit. I also agree with the authors quoted at the UGA article that this is not a problem that has recently come up, but has always been there.
