Where is the point in cycling if you don't have to use your own muscles to ride?

Because sometimes you have the energy and sometimes you don't. Sometimes you're ok with sweating and sometimes you aren't. Some days are 100F degrees and some are 60F. Maybe you're not strong enough to maintain your speed up a hill by your house but you're ok for the rest of the trip. It might lower that one part of the trip from "too hard" to "doable" and it's one more person getting more exercise and driving less.

It's good if everyone bikes more but the whole point of a commuter bike is that the exercise part is secondary. First is getting from point A to point B daily and conveniently.

In the case of the vehicle in the article, it is transportation.

For instance, I live in the Puget Sound area, across from Seattle. If I were to get a job in Seattle, my commute would consist of driving my car to the ferry terminal, paying something like $15 for transportation for me an my car to Seattle, then driving on to work. Reverse the process to come home. $30 in ferry fees for the day.

With a device like the one in the article, that could be changed to driving my car to the free park-and-ride lot near the Ferry terminal, riding the bike to the terminal, folding it up and going on as a walk-on. In Seattle, I could then unfold the bike and head on to work. Reverse the process to come home. The ferry fee for walk-on passengers is $7 in one of the directions, and free in the other direction.

In under a year, the $23 per day saved in ferry fares would pay for the bike.

A regular bike would simply not work for me for this. The hills in Seattle would be too much for me.