Yes, there are good reasons to use class hierarchies but they don't pop up all the time. For example recently I've used it in tsql [1] - template sql combinator

Yes, there are good reasons to use class hierarchies but they don't pop up all the time. For example recently I've used it in tsql [1] - template sql combinator library; inheritance is not a big part there, just a small bit where there is sanitised-identifier class that's a child of a sanitised class. Some combinator functions require sanitised-identifier (unusally table name) but most of combinators don't care; as long as it's sanitised value they're ok with it. It's good to have flow keeping track of this relation and reporting violations. [1] https://github.com/appliedblockchain/tsql/ https://github.com/appliedblockchain/tsql/