Once again it's a reactive decision by a government. The world over governments are plagued by reactive decisions rather than proactive ones. If they were proactive then this whole pandemic "might" have been managed better.
The problem is not enough studies have been made in important areas to categorically state an answer. For instance "if" I had been categorically told it was proven that a 52 year old male diabetic with an HBA1c of under whatever number was at no more risk than the rest of the population then I wouldn't have left work.
Same with this "do they" don't they" debate on whether children spread the virus. "If" children over 6 years old spread the virus then the argument could be why wasn't masks wearing made mandatory in children months ago? The other side of the coin would be "can" children of a young age, between say 6 and 10 be able to wear masks for a length of time? As many of us will point out, it is a pain wearing them for six hours or more and most of us probably do the wrong thing with them anyway, like taking them off, putting them back on, etc etc, so how is a 6 year old going to cope? On top of that it's possible, although I doubt it, that children under a certain age don't spread the virus, but this panicked governmental decision suggests that they do, unless as I say the particular studies haven't been done properly.
I find it staggering that months into this pandemic studies are still a wishy washy, dunno, maybe, possibly. How on earth can you do anything proactive or deal with the situation if you just don't know?!