What's the point of Firmata?

Why would anyone need Firmata when you can communicate any arduino data easily using serial? Also I read somewhere that Firmata is pre-loaded to the firmware on all Uno r3 boards - so why would I also need to load Firmata.h library? Am I missing something?

I thought the purpose of Firmata was to allow you to monitor and debug your running arduino sketch from a PC.

Also I read somewhere that Firmata is pre-loaded to the firmware on all Uno r3 boards

Where? It is not true.

so why would I also need to load Firmata.h library?

If you are going to use Firmata, you need the header file at compile time. Not that I recommend using Firmata, mind you.

Why would anyone need Firmata when you can communicate any arduino data easily using serial?

Some people don't have the skills, patience, or mindset to develop their own protocol and to implement it.

I thought the purpose of Firmata was to allow you to monitor and debug your running arduino sketch from a PC.

No idea where you got that erroneous impression.

I think warren631 is referring to this statement from this page http://firmata.org/wiki/Main_Page

Arduino Uno

All Arduino Uno boards come with StandardFirmata 2.2 pre-loaded.

Well, the Firmata people need to update their site then.

Firmata is part of the standard libraries. It is not loaded to the arduinos, but available in the IDE without extra download.

The idea is to use a MIDI-like protocol to remotely control an Arduino. The program on the PC sends something like "NOTE 3 ON", and the
output D3 goes ON. Other controllers allow to use PWM and ADC as well.

Not many people are using it, and prefer to put the intelligence in the Arduino instead of making PC programs.
It's just there (like SD, Ethernet or LiquidCrystal) if you want to use it.

It's just there (like SD, Ethernet or LiquidCrystal) if you want to use it.

It is, but unlike those other libraries, it isn't supported.