Why would anyone watch all the matches of the IPL? (Except it's related to their jobs)
How many times we watch all matches in the World Cup? Even hard core cricket fans don't follow every team's fixtures in the WC as they focus in high profile games, casual cricket fans only follow rivalry-matches only and so it's a same with the IPL.
I don't think so, because of the timing in which IPL matches start. Around 7:30 pm the match begins. This is the time by which most of the people sit to watch what have taken place around the world. During the time of IPL fixtures, the people who are watching the world happening will start watching IPL matches. One day if it interests, the next day onwards particular person will sit to watch IPL.
In Indian context timezone argument is correct as it's a prime time slot and families do get together and watch some action during dinner or so but no one can sit 4 hour on the trot for month. 1-2 hour yeah sure that happens all the time.
Not counting other subcontinent nation. Oceania countries especially Australia and NZ hardly watch IPL due to timezone (IPL do have fan following tho) unless someone has some stake in it like their fav players, franchise etc. Eng,SA,WI etc do have fair amount of audience but majority of em only follow their local players.