Here's my thinking
Small: helps with space, cost, portability
Own: save time and cost to go to shop (very expensive) . We are very busy. Business charges a lot here to do anything simple, In fact, they may not cut anything due to low business demand for it.
Usability: it certainly helps cut metal quickly and quieter, less dust than angle grinder, and nicer cut.
Frequency: with metal, it is used alot to begin many projects.
Availability: we can cut it off business hour, especially for working people doing hobby projects