Over the past 12 months I have taken 14 longhaul flights with Iberia, all but 2 were in Economy and I have to say that they are no better or worse than other European airlines.
I have found the staff polite and attentive to requests. I wonder if what is judged as rudeness is a cultural difference. In Europe there isn't the over the top fake politeness of Americans or the encroaching desire to help of the Asians.
I had one case of a flight delay, bad weather in Bogotá and the missed connection couldn't have been handled better. And the one case of lost luggage was handled perfectly as well.
I'm not Spanish and have no link to Iberia, so I am objective and I must say that I do not understand all the bad press they get, industrial action aside.