Performance is not a feature. Decisions about performance are part of every line of code we write. Some developers make good decisions and do their job right, many others half-ass it and we end up with the crap that ships in most places today.
This “blame the managers” attitude denies the agency all developers have to do our jobs competently or not. The manager probably doesn’t ultimately care about source control or code review either, but we use them because we’re professionals and we aim to do our jobs right. Maybe a better example is security: software is secure because of developers who do their jobs right, which has nothing to do with whether or not the manager cares about security.