Invariably, these people are full of "rational" and "honest" criticism ... but only outbound. They don't take the exact same kind of inbound criticism nearly as well themselves. Nor do they ever offer any honest praise, encouragement, or support. These asymmetries give the game away. It's just an excuse, put forward when convenient and taken back when it's not. A truly honest person would not be so selective about which truths to tell, or to hear.