I don't agree that an attacking player losing the ball in and around the opponents penalty area when making a decent attempt to break through their defence should be blamed for a goal that follows when there about 7 or 8 plus players who are there to defend it. If players get criticised for that, they may not attempt anything, and that is far worse. Of course there are exemptions like continually losing it, and being over adventurous when hanging on to a goal lead etc.
But I thought Kranjcar had a decent game when he came on for Vargas against W Brom, looked in reasonable shape, and set up the 2nd goal, but he was poor at Villa, looked slow and perhaps the game came too quick for him after W Brom. I suppose it's normal that a player has some good games, and bad games, but perhaps we have had anyway too many that are variable, possibly they haven't been fit enough.