GM, and indeed the other two of the Big Three, spent the 70s, 80s, 90s and most of the 00s making the worst small cars in the entire world. The only reason they didn't make the worst small cars in the entire world in the 60s and earlier is because they didn't really make small cars back then.
I'd beg to differ. It may have a big heavy V6 right over the front wheels, but that old Sunbird is still fun-to-drive in its own way. Simply becuase of not having some obnoxious drive-by-wire system at work, that car will accelerate or decelerate as roughly as you care to make it. If you manage the clutch and throttle smoothly, it'll move smoothly, but if you stomp on it, it'll go, no waiting or smoothing whatsoever. And it makes me wonder, "why is it so difficult to find a cheap car that's practical, yet still lets you drive this way when you feel like it?"
In the last few years, each of the Big Three has turned its affordable car lineup around completely and now competes with success in those lower sectors. Granted, some of that is because the Japanese have forgotten how to make good small cars and half of the US ones have been developed in Europe, but still.
Save for the Spark, which is awful wherever you're from, there's nothing wrong with any of the cars you mentioned. Certainly not compared to the stuff that came before. That's progress.
Depends on your point of veiw. The Spark, to me, is awful before you even get to how it drives. It's a microscopic car with a microscopic engine and a long list of "cute" colors that apparently change yearly to stay trendy or something. The Sonic isn't
too bad, but some elements of the styling could use a bit of work, specifically the sedan's messed-up proportions. The Cruze's engine, though appropriate in the Sonic, is
far too small for a 3,000lb car, and puts out less horsepower than the
base engine of its predecessor regardless of what you think of displacement downsizing. The goofy styling is the final straw for that car.
The Impala is fine as an appliance, but if I had the money and the intent to buy a full-size sedan, I'd skip the new-car lineups entirely and find a used Pontiac G8, or wait for the Chevrolet SS (AKA "faster version of what the Impala should have been in the first place").
That "American RWD lineup" you lust for doesn't exist because it isn't commercially viable. The reason the entire US auto industry almost collapsed during the financial crisis and needed bailing out was partly because the automakers got complacent and thought that building low-quality, ancient junk would work forever.
Do you really think the G8 is a "low-quality" or "ancient" "junk" car?
More relevant to this thread, crossovers are another bit of "progress" that definitely didn't progress in the right direction. A crossover is, effectively, a station wagon that's taller, heavier, more difficult to maneuver, slower, uglier, and uses more gas, created only because the way CAFE was set up didn't really make much sense.