> Remember that at the start, all the 'experts' were happy to say masks would have no effect!
You are oversimplifying. At the start, we did not know if it was propagating with droplets or through the air. Masks do stop big droplets and are effective in that case. It seems like it was not so much droplets in the end, so the efficiency of the masks was limited (but I don't think you can conclude it was zero). But also let's not forget how stupidly people were behaving during the pandemic. It went further than just knowing how the virus was propagating: there was a whole part about people's behavior.
> I read a lot of mask and epidemiology papers during COVID. They were all terrible. Standards in computer science are much higher
Let's be honest: most papers are terrible. Maybe you're biased because you know how to select good papers in computer science (or maybe you understand epidemiology better than computer science :-)), but most papers are terrible everywhere. That's why it takes expertise to make sense of them: if you just blindly trust whatever you read because it looks like a scientific paper, then you're in a bad position.
> so this belief that Lemire shouldn't be allowed to have opinions is kind of entertaining.
I don't have any idea of the quality of Lemire's work. This particular article doesn't show anything interesting IMO, though. Also I did not say Lemire was not allowed to have opinions. Just that when you are in a position of authority (a professor in a university), you should know better than to just throw a link to a paper together with a half-baked opinion.
It means they don't need to be in academia at all. That is the explicit goal of open access.
> But the target audience of a paper is quite obviously other experts in the field.
It doesn't matter who academics would like their audience to be, the actual audience is anyone who needs or wants to read it. That's why they get given grants and why the open access movement was created.
> Not to mention that even if we could say today that masks were not effective, it does not mean that back then it was a ridiculous decision
Remember that at the start, all the 'experts' were happy to say masks would have no effect! If you dig in and look at why they were saying that, it's because masks would have no effect (and didn't). Their step change came after political pressure to agree to masking both from within and without, which they just immediately acquiesced to apparently due to the strange belief that such things don't have any downsides. All this has been well documented.
I read a lot of mask and epidemiology papers during COVID. They were all terrible. Standards in computer science are much higher, so this belief that Lemire shouldn't be allowed to have opinions is kind of entertaining.