I read to the end of page 1 before realising this thread already has 14 pages. I don't have time to read it all now, but I did want to respond to this.
Competitive games (wanting to win, keeping score)
Physical exploration (climbing, jumping, testing limits)
Object-focused play (building, vehicles, tools)
These are all things which are encouraged in my Reception classroom. They benefit all children, boys and girls, and are essential for them to achieve some areas of the early years curriculum.
Rough-and-tumble play (wrestling, chasing, mock fighting)
This is the bain of most teacher's lives. It's simply not appropriate to have children jumping on top of each other, pinning each other to the ground, karate chopping and kicking etc. As some people have explained in the first page alone, and I'm sure many more on subsequent pages too, it's impossible to regulate. What starts off as fun and games always ends in tears or bruises. Children all have different levels of strength and pain thresholds. What is fun for one is painful and upsetting for another. What excited one, scares another. For every parents who say "kids will be kids", another wishes to report relentless bullying if their child is constantly coming home complaining of being hurt by the same child, or is scared of certain children because of how roughly they play. Kids have no idea that the level of force they wrestle dad or an older sibling (for example) with hurts their smaller same-age friend. Larger relatives are naturally more gentle with them, but suddenly a larger same age child dives on top of them and it's going to hurt. Schools simply cannot allow play fighting for all these reasons. They are not failing boys (or children in general) by directing them away from this type of play. It's not appropriate, because it's dangerous. For every parent who would be happy for school staff to stand back and allow children to engage in rough play fighting, there would be another who would be outraged that school allow it to happen. Rightly so in my opinion.
Chasing games are completely different (I'd put them in the competitive games category myself), as long as the child doing the chasing is simply tagging rather than wrestling/jumping on top of someone when they catch them.