After the last paint job on our block building, the paint is failing and the mortar and block is too. One contractor suggested moisture from inside of heated office areas was causing outside to fail. Inside is sheetrock and has never been an issue since 1978
Paint peels when moisture gets under the film and causes pressure. The moisture has to be coming from somewhere but the paint didn't cause the failure of the block, excessive trapped moisture caused the failure. This type of failure, crumbly block and mortar, takes time to develop. Look at all areas that moisture can get in; cracked caulking around windows and doors, roof flashing, etc.