I think that very few people watch entire test matches nowadays. Most of us switch on the TV once in a while to check the scores and may be to watch half an hour or so of play while having tea. I am someone who work 5 days a week. Yesterday I watched the T20 match between Namibia and Papua New Guinea, because the timing was suitable for me (9pm - 12:30 am), and the duration was short. Today is holiday for me, and I am planning to watch the two T20 matches (final between Netherlands and PNG, and the 3rd place match). If a test match was ongoing today, then I would have skipped it.
The ICC needs to understand that T20 is a format that is more suitable to the modern lifestyle. Ideally they should increase the number of the T20 matches and decrease the number of ODIs and tests. What is the point in having each country play 8-10 tests every year? IMO, this number should be reduced to 3-4 matches per year. And one thing to remember here is that a T20 match brings in almost the equivalent amount of revenue when compared to a test match.
Cricket needs to move on. Clinging on to the traditions won't work.