First of all – who doesn’t love more football? But to actually dive into the reasoning why there are so many bowls (like are beloved Bad Boy Mowers Bowl or the Bahamas Bowl), you need to look into the benefits of a bowl game and how teams qualify for a bowl game.
One very short answer of why there are so many bowls is that there’s a lot of money to be made off of them. Networks, especially ESPN, make a great deal of money from broadcasting these additional games. Furthermore, they bring money to the local economies that host them, which can have an especially strong impact when it’s a city like Shreveport or Birmingham.
Another reason is that the teams themselves want to play in them. Never mind the fact that it offers the players an opportunity to be rewarded for a winning season and travel to a destination (of varying quality, to be fair), but coaches love bowl games because it offers the team additional weeks of practice, which will help them get even better for next season.
As far as having over 40 bowls, a good reason for this many college football bowl games is that a winning record qualifies you (i.e. going 6-6 or better), and the current number of bowls practically ensures no teams with that record get left out. It’s always a sad moment when a team goes 6-6 but gets left out because the bowl selection committee decides they wouldn’t drive enough revenue (once again, money drives the whole process), so it’s nice to have enough games where this doesn’t often happen. In the even there’s not enough 6-6 teams, 5-7 teams are selected based off APR (an academic rating).
So, why are there so many bowl games? Because they make money, coaches love the extra practice it gives teams, and it allows every qualifying team to play in one. But, why are you asking this – who doesn’t love extra football games?!