Yes, baseball has to put up more netting to keep fans safe. Baseball has been lazy in protecting fans from being hit by foul balls. They should have put up more netting years ago. Netting should be installed in front of all foul line seats in the stadium. That would make it safer for the fans in those seats.
While I am unsure if additional netting is the answer, I do believe that more protection is needed for fans at baseball games. Sure I completely understand the thrill for the fan catching the foul ball. However not everyone in the stands is necessarily a good catcher and even if you are, it is easy to imagine your head being turned away and not even seeing the ball coming. Those balls fly fast and can definitely cause injury.
There are high numbers of people being injured by a foul ball. The fun of catching a foul ball does not make up for the potential injuries that people can receive. This includes to children who did not themselves make the choice to go to a baseball game. The teams can do more with protective netting. They choose not to.
Very few fans have ever been hurt by foul balls. Netting would change the game in a number of ways. If the ball hit the netting it might not be a foul ball anymore. It is also a great tradition that fans are able to catch foul balls and keep them.