The problem is with the philosophy. Some examples.
If, like me, you believe that markets exclude poor risks efficiently, then you must think that applying market forces to healthcare environments will efficiently exclude sick people from the services they require. I believe that is bad for everyone - current consumers of healthcare (the sick) and potential future consumers (everyone else_. And folks who say "let the market decide" are making a choice that is thoughtless and actually evil in its effects (even if evil isn't the intent).
If, like me, you noticed that charitable giving by individuals failed to grow countercyclically to a useful extent when the economy crashed in 2008 causing 600k jobs per month to disappear, and you believe in trying to save people from unfortunate harms that they cannot evade (ie no jobs available), then you kinda know that government is the only agency capable of growing to meet the need in such circumstances. If, on the other hand, you conclude that charity is adequate to meet the need, and you turn out to be wrong, then your original idea was callous and damaging (even if it wasn't your intent).
If, like me, you think there are such things as negative externalities, such as releasing coal slurry into a river which pollutes everything downstream, then one perspective is that businesses which do this are imposing costs on their downstream neighbours and on the environment. In allowing this to occur, folks are doing something which is socially unpleasant and environmentally toxic (even if their intent was to put miners to work). (I accept the fact that jobs are also worth something so this is a relative thing - but the externality still isn't free)
So I am not talking about individual people. I am talking about beliefs that do damage, even though the believer is the most benign person in the world. Even saints do incredibly wicked things entirely by accident.