No they're not. Not every command line tool uses flags, some use ordered parameters. So parameter 1 might be a file name to write to rather than a flag. Just look at how messy it is working with tools like `cp` and the `--` flag to get an idea of the problems some programs face differentiating between files and flags.
Other tools might not take any command line parameters at all. So it's entirely forgiveable for them not to check if any parameters were supplied.
Then there is the issue that some programs accept `-h` and others `-?` as a shorthand. Some programs have `-h` as short for `--host`.
Plus even if I were to agree with your point, which I don't, it's entirely moot because it's not the author of the tool that is the one who has to fix any issues that might happen to a host system due to someone blindly running commands.
So whichever way you cut it, blindly throwing flags at executables and expecting a favourable outcome every time can be risky.
> Many applications that are installed outside the scope of a package manager, especially tools distributed as a single binary, lack a manpage.
That point wasn't forgotten by me. But if you've downloaded an application outside the scope of the package manager then you should at least have some idea how it functions and thus know whether it's safe to run `--help`. If not, you probably know where to look online to find that information out.
Like I said in my OP, I've got nothing against people using `--help` et al. I use them myself. But it shouldn't be the first thing you recommend UNIX newbies to do when they're figuring out a command. It's usually something you do when you're already familiar with what a command does but need a nudge as to what flags you need to supply.