I like the model (and the accoutrements), just not a fan of the real deal.
I guess I'm drawn to ugly, slug-like designs. I've always like the split grilles on Pontiacs, and the Astre and Chevette/Acadian both had 'em:
I tend to gravitate toward hatchbacks and cars with fastback rooflines, too, so even the 4-door Chevette has some appeal to me. I think their simplicity is also appealing, but you're right in that they are definitely and entry level car, devoid of almost all creature comforts and luxury options...which is probably why they got 40 mpg.
This is just about the frumpiest car you could buy in '77, but the oddball Sandpiper package has a unique appeal to me. I guess growing up during the "flares and tape stripes" era has had a lasting effect on me.