after reading posts on many alfa forums, the reputation comes from this
the reason why a lot of alfas were unreliable and broken, is not because of the build quality itself, rather it was built to be broken, in a sense. when trying to make their car's more exciting, they asked themselves, how can we make them seem faster? ok lets build the chassis in a way so that the car will wobble and shake more than if we built a very strong one. as a result, many of the reliability/quality issues result from the way they designed the car.
that being said, alfa realized the problem, and the 147, 156, 159, mito, spider, brera, GT, GTAs all have reinforced chassis.
the ones that break down, tend to be the older GTVs, old spiders, 155s, 146s etc etc
srsly, the spider looks the best, and the newer alfas are as reliable as other makes.