The reason why this is vital is that when working on large SCO projects you need a way to easily build your Thingworx application. The common way in the industry is to use Excel sheets that can be exchanged with machine suppliers and then imported into Thingworx. In a production line with several IMM machines, robots, assembly stations, quality stations and printers there might be 2000+ properties that needs to be created. And a site might have 50+ production lines. So the ability to be able to autocreate everything is vital. And since many machines are very custom, there is no way to set it via a template.
The limits and egu is often used in trending components so that the Y-axis range and label can be set automatically and that is why it is important to have this feature.