There are a lot of reasons why there are many languages. In many cases it comes down to an effort to fix a specific problem with an existing language, while in others it comes from someone being unhappy with the tools that already exist.
Java was invented to try to correct some specific problems with C++ that can cause problems in some cases. Perl came when Larry Wall was unable to use sed and awk to fix a problem he was having running some systems. Lisp started out as some formalisms in math.
I have over the year or so really been making a strong effort to try to improve my skills as a programmer and have been working a lot on the theory side of things.