I don't think anybody is saying that 2011 was because of bad luck on Hamilton's part. If anything, we're all saying the same thing; he was the master of his own undoing back then.
But this season? Hamilton's issues have been out of his hands, hence the "bad luck" that everybody has attributed to him. But Button is a different story. If his pace issues were purely down to setup, then that's his problem and his alone. It's up to the driver to get the setup right, if we're to believe Hamilton's detractors after Spa qualifying and after Japan, even when it became apparent problem was actually a part that failed in FP and nobody noticed.
Ofc, the team has no involvement in setup.
If I remember correctly the roll bar was Korea and maybe Japan.