To a degree, so definitely something to be aware of.

For example, the Toyota Matrix is largely a Toyota Corolla, but was made as a joint effort with GM. Because of this it suffers from some poor design choices that come from the GM side.

It's still a far better vehicle than any GM product.

Around 2000 Honda bought the Isuzu Rodeo and rebranded it as the Honda Pilot. Because this is Honda, they didn't re-brand garbage but rather a vehicle that was already at 1990's Honda reliability. It was equivalent in overall quality to a 90's Honda Civic. Good vehicle, but on the lower end for ride quality, noise, etc. Those things ran forever (Isuzu built incredibly reliable engines).

Today the Pilot line is fully engineered by Honda and shares parts, drivetrain, etc, with other Hondas. There's nothing Isuzu left.

Even the Geo cars of the 90's (joint projects of GM and Toyota) were way better than GM cars.

So while you make a point, it really has very little bearing on the Japanese big 3. Even their joint project cars are far better than American or European garbage.