For the same reason that they can say not to use lead paint, or asbestos siding...
Europe found itself in a huge conundrum last year when Russia cut off the gas supply, highlighting our dependency on cheap Russian gas. It meant households went cold and lost their primary means of hot water and cooking - not so much because there was no gas, but because it was unaffordable.
But in my neck of the woods, removing dependency on gas had been ongoing for a while already for various motivations. One reason to do more with electricity, for example, is because people have cheap solar panels on their roofs now, using that to heat their house is (seems?) more self-reliant, cheaper, and less environmentally impactful in the long run.
And sure, one house won't make a difference, neither will a thousand. But it'll start to make an impact at scale.
There is no one fix for climate change, it will take tens of thousands of small changes and legislation over the span of decades.
Also, just because searing protein produces bad indoor pollution, doesn't mean that any other pollution should therefore be automatically ignored. It is purely optional whether you want to use your stove to sear protein (e.g., you won't find any vegans using it for that purpose), but you don't really have an option if the only thing installed is a gas stove to heat your tea water or saute your onions...
A cheap electric kettle or standalone burner is an option, isn't it?
And doesn't the research indicate that fume hoods help regardless?
And what about when you want to bake or broil something?
& yes, fume hoods do help, with "help" doing a lot of heavy lifting in that sentence. They also need to be turned on to work (not likely every time you heat a pot of tea), and are noisy, and waste even more heat, blowing out cubic meters of already heated/cooled air to exhaust milligrams of pollutants. Always better to never generate the pollutants in the first place.
And for the societal-level goals of reducing climate change and improving public health, it is best to do it at a societal scale, not making every individual go and spend resources to redo and workaround the work that has already been done. Far better to just not install the polluting infrastructure in the first place.