A lot of people had the idea of porting over the hugely popular Western concept of franchise league tournaments. Thats where the ICL was born. But somehow they had run-ins with the then BCCI establishment and Lalit Modi was an office bearer at that time, and so he was tasked to create the official version of the ICL, which then became the IPL. They tagged ICL as the 'rebel league' and ostracized it and then they created the BCCI version of it and called it 'IPL'.
The concept of franchise leagues is inherently very exciting. You have these private players own teams and hire players, trade players, win players, etc. Its a great form to watch the sport without all the morality aspect of supporting a country, etc (believe me, I am ever so slowly moving away from the passion of supporting/following Indian cricket, as I know these leagues exist and I get my fix of the sport from them). That's how it works in USA - the most popular tournament in USA is the Super Bowl, which is basically a city based franchise football league consortium. World Cups are not as popular in USA as the Super Bowl.