I love Argento, but it's very difficult to fault anyone, even horror fans that don't. Heck, even Argento fans themselves are divided by his films. Personally I thought that TRAUMA was his finest work since Bird With the Crystal Plumage but most Argento fans think that Trauma stinks to high heaven.
That said, I have all but given up completely on him. He hasn't made a good film in a long, long time. Sleepless was a mild step in the right direction and Card Player was just partially interesting but for the most part, his few stuff sucks. So much so that I didn't even bother seeing Mother of Tears and unless the world "GIALLO" is stamped on any of his future films I will likely not bother at all.
Same with Romero, Carpenter and so on... seems that as horror directors get older they loose their way. Sad but true.