Strange if that is true, because in seasons 2012, 2013 and 2014 Nasri has been in the top 5 list of most final third passes in the league, being 2nd and 3rd in the last two years. And accuracy wise he has been at a constant 90% in final third passes accuracy, once being the leading passer in the league. I'm not sure exactly when but I assume it was in 2013 when Silva got injured and Nasri deputised, earning him that months PL player award.
And with the backwards and sideways pass, Nasri's data has him at 61% forward pass accuracy, an above average high for a midfielder. Admittedly, he had a horrible backwards pass spell against Juventus so I guess that has burnt the image into everyone. In terms of passing however, he is the only player in the PL to have such record over the recent years, more than Silva. Arguably they add different things to the mix, but Nasri during his prime was certainly not an average player. He was also playing with the likes of Garcia and Milner so that puts things into perspectives.
He is now a squad player I agree because we have better players now.