Typically inflammatory first par, using that old chestnut 'slam'.
From the quotes I'm seeing, Flower isn't slamming Malinga's decision at all. Seems like he's more rueing the fact that players are more and more moving towards this type of decision.
And in the unlikely event he is slamming him, he has no right. Malinga has a loyalty to himself, his family etc before he does to Test cricket. If he's injury-prone and he can prolong his career/earnins through limited-overs cricket, then all power to him,