Why was pinball invented?

In 1871, British inventor, Montegue Redgrave was granted US Patent #115,357 for his "Improvements in Bagatelle". Bagatelle was an older game that used a table and balls. Redgrave's patented changes to the game of Bagatelle included: adding a coiled spring and a plunger, making the game smaller, replacing the large bagatelle balls with marbles, and adding the inclined playfield. All common features of the game which later became known as pinball. Pinball machines appeared in mass, during the early 1930s as countertop machines (without legs) and they featured the characteristics created by Montegue Redgrave. In 1932, manufacturers began adding legs to their games. "Bingo," made by the Bingo Novelty Company, was a countertop mechanical game released in 1931. It was also the first machine manufactured by D. Gottlieb & Company, who were contracted to produce the game. "Baffle Ball," made by D. Gottlieb & Company, was a countertop mechanical game released in 1931. In 1935, Gottlieb released an electro-mechanical standing version of Baffle Ball with payout. "Bally Hoo" was a countertop mechanical game with optional legs released in 1931. Bally Hoo was the first coin-operated pinball game and was invented by the founder of the Bally Corporation, Raymond Maloney. The term "pinball" as a name for the arcade game was not seen until 1936.