Comment by arendtio

Well, if it would be just bad, why do we still use it? Why don't we use e.g. Python (which is a much better designed programming language)?

Some reasons why POSIX shells are great:

- they are part of POSIX (a Standard which is implemented by multiple OS) and therefore often available

- you can use them to compose programs written in different languages

- you can easily connect the output of one program with the input of another (pipes)