Just because they were optimizing for length doesn't mean they threw mnemonic potential out the window. And either way it's quite arbitrary because almost all

Just because they were optimizing for length doesn't mean they threw mnemonic potential out the window. And either way it's quite arbitrary because almost all command names are still based on English that is a second language to many (including yours truly, but I'm not complaining, I find the usual unix shortcuts rather nice and intuitive most of the time and most of all - extremely quick to write, PowerShell makes me shudder and I had such big hopes for it). Many concepts are also unique to unix/computers/low-level usage so any name will be non-intuitive. If you never encountered the concept of mounting a filesystem and don't know what an inode is then 'list inodes too' and 'list mounted filesystems' are no better to you than 'ls -i' and 'df'. And someone who knows will prefer the latter, because it's that much quicker to type and harder to mistype.