The landing strip theory has always felt a bit too convenient to me, like it was built backwards from the conclusion someone wanted. The lines are impressive but they're not flat or stable enough to land anything on, and that was true even before erosion. The geoglyph shapes - animals, spirals, figures - don't map onto any functional runway logic either.
That said I don't think the theory is dead so much as it never really had legs to begin with. What's replaced it is more interesting anyway. The water/ritual procession angle has a lot more archaeological support now and fits what we know about Nazca culture and the surrounding landscape.
What I find genuinely strange is how people keep returning to the alien hypothesis every time a new documentary needs ratings. It sort of poisons the well for anyone trying to have a serious conversation about it.
Anyone here been out to Peru and seen them in person? Would be curious whether the scale changes how you think about thier purpose.