That's actually utter bs. First of all, Spanish Barça fans think of him quite highly, despite of the odd mistake here and there. Yes, he has made more errors recently, but that should in no way take away of what he has achieved, what he has done, and what he will keep on doing for our team. He's not in any way more mistake prone than any other top keeper. Have you seen the howlers / blunders made / let in by Stekelenburg, Casillas, Neuer, Cech, Buffon & co?
Second, neutral fans are in no way different than the Barça fans on this forum. They have a divided opinion of him, which luckily leans more towards him being a solid, great and WC keeper. He has proven a lot of people wrong over the past years, and it shows. And this is only an observation I've taken discussing him with plenty of my mates living around the world who support their own distinctive teams.
The fact that our own fans can't seem to give him the credit he deserves is, frankly put, appalling. What's even worse, is that people seem to pull accusations out of thin air with no factual or empirical data to back up their non-existent theories. Skating on thin ice seems to be the trend this year.