That's my point: the language cleanliness may obfuscate dirty implementation details, and a good developer should know what these are. Another example, when yo

That's my point: the language cleanliness may obfuscate dirty implementation details, and a good developer should know what these are. Another example, when you do this: SuperLargeList.Where(x => x.Blah).ToArray() There is no way for the compiler to know whether the output array will have a small size or a large size, and so it will choose one or the other assumption (dynamic vs fixed allocation). The language chooses for you how it implements things, and this is all fine as long as you know about it, and as long as you can do something about it in the case when you need to optimize.