I am not sure you completely understand the reality and the need a lot of average commuters have for gears and clean untorn pants...

Once I can afford to, I will build new wheels for my main commuter with a nice 11 speed IGH and full coverage chainguard. However, I am dealing with the 12 speeds and derailleurs that my bike came with. Most bikes in the US come with derailleurs, so a lot of us are trying to deal with that fact.

That said, I can see the chainline and trim on my front derailleur even with my chainguard installed since it has a little bit of a cutout there. My mixte is a heck of a lot lighter and more nimble than a dutch bike for the mega hills I need to climb in Seattle. I still want to do so with a little style, hence the chainguard. I think if you ride indexed, you are less likely to pay attention to the status of your trim and chainline than if you have a little chainguard installed.

I have a Raleigh 3 speed DL-1, and I fully intend one of these days to fully enclose the chain like it was meant to be. My three speed, is still more of a toodling down the MUP kind of bike than a hill climbing get around town beast.