Most times when been carried in a matatu, your knees will either lack enough legroom, you will have to fight for pace with the spare tyre and excess passengers and Worse of all, some of this guys will drive like they are participating in some reality show. If you are a passenger in a matatu that suddenly changes lanes at top speeds just undercutting some truck on mombasa road, then changes back to the spot it was for no reason, you cannot wait to buy your own car before you end up as a statistic. 

At some point, you get afraid of sitting at the front or just behind the front (I mean, the engine has to move after an impact. Then you look at the amount of metal that goes into making matatus , metal seats, metal decorations and add the unsecured spare tyre at the back. At this point, you begin praying for a safe journey. Safety regulations and physics are things people do not understand.