A $60 flashlight is likely to be a high current drawing one, which means you are not going to want to use a protected cell in it to begin with as that would only reduce current flow.

A spring introduces a potential current bottleneck. In the race to obtain max lumens, elimination of a spring helps deliver more current to the LED. If you are going for max current flow, you will stay away from protected cells anyway, so it becomes a non-issue.

A protected cell will be closer to 18690.

Besides, a flashlight manufacturer doesn’t control what cells and what protection circuits are available on the market. New cells come out all the time with varying lengths, depending on what kind of protection circuit a third party decides to add to the cell. If they have to make a flashlight that accepts a wide range of cell lengths, it will be a compromise that many people are not going to accept. You can never please everyone. With that said, there are plenty of lower current flashlights that are not picky about cell lengths - Convoy S2+ for example.