It really, really depends on what the comment is saying. Comments that explain what the code is doing are usually a travesty. With the possible exception of ha

It really, really depends on what the comment is saying. Comments that explain what the code is doing are usually a travesty. With the possible exception of hairy performance optimizations. Also implementations of algorithms that aren't well known -- oftentimes the original paper is dense, academic and behind a paywall, and the Wikipedia article are a muddled mess. You really owe it to your readers to give a sane and comprehensible explanation instead. Comments that explain why the code is doing what it does, though, are HUGELY important. There's nothing worse than coming into a legacy codebase and seeing it littered with obvious special cases and workarounds that are all undocumented, so that you have no idea what they're for or whether they're obsolete or not. Skipping these kinds of comments leads to inexorable technical debt, because eventually you'll end up with a codebase where everyone is afraid to change the code.