That's definitely a thing, and you're right, it doesn't add much entropy (people choose from a few numbers, a few special characters, not that many substitution

That's definitely a thing, and you're right, it doesn't add much entropy (people choose from a few numbers, a few special characters, not that many substitutions). Four extra characters that are truly random (even just out of 26 letters) is way better. However, that's not the alternative I'm worried about. I'm worried about people using phrases that will be in the first few thousand entries in a phrase dictionary.