I suspect a lot of people bought .40 S&W handguns back when it was the darling of many law enforcement agencies after the FBI had decided that the 9mm Luger was "inadequate". I also suspect that many of these folks bought 40 calibers without really having much experience with the round, or bought small pistols chambered in a caliber that was not really all that suitable for them.
Perceived recoil is a highly subjective thing and I think the key to becoming comfortable with .40 S&W is to have a pistol of sufficient size and weight to handle the recoil easily, maintaining an excellent grip, and just becoming more familiar with the recoil characteristics of the round. I do agree that the recoil of the .40 S&W cartridge does tend to be sharper than 9 mm Luger, or even .45 ACP, and it might not be the best choice for those with arthritic hands or wrists, or limited hand strength.
Many of us have become comfortable shooting .40 S&W, shoot it accurately, and don't plan to stop doing so.