[Alex3917]

Most high-level rowers develop back problems, but these aren't primarily from the rowing machine, and your chances of developing the same kinds of problems while casually working out to meet your daily fitness goals are basically zero.

E.g. almost all high-level swimmers have shoulder problems, but no one who just goes for a swim a few times a week is going to injure their shoulders. Almost all baseball players have ankle problems, but no one who plays baseball with friends after work is at risk of this.

The reason rowers get back problems is basically a combination of overuse, the asymmetric load-bearing motion of sweep, and underdeveloped antagonistic muscles. Given the device and the target market, none of these issues are really at play here.