...because they remind me of the incredible potential there is for interesting stories and ideas in the Haloverse and the way that potential never gets capitalized on. This is probably because most writers hired to write for Halo aren't science fiction writers and are uncomfortable with ideas that fall outside their experience of mainstream SF like Star Trek, et al. So the more alien races like the Lekgolo just disappear for the most part so we can get more of the same old UNSC vs. Covenant formula.

When we do see Lekgolo in an unusual context, they're just a mindless monster of the week with no agency (ref: Nightfall). As this thread shows, they have potential to be much more than that.