I currently have 8 e-ink readers with front lights. Probably half a dozen of my neighbors have half a dozen more. I've yet to see one with dust between the light and the e-ink. That might be a problem with Tolino. I've never seen one of them. It's not a problem with Kindles, Nooks or Kobos.
I also don't need a front light. I read a lot of books before I got a reader with a front light. But it sure does make the reading better and now all of mine have front lights and I'm not likely to get any for myself in the future that don't. It's not that it's really needed. It's just really really useful.
I don't really need a computer, either. But I'm glad I have one. Wait, I have several.
It is true that front lights cost more and if you really don't care about one I can kind of see your point, but I doubt you'll find a really good screen without one.
Barry