Difference between installing a program in ROM or RAM?

[a4111]

Can someone clarify something for me please?

From what I have discerned reading the web the "program memory" basically has some memory dedicated to running programs (RAM)... the "storage memory" stores the bios + windows mobile 6.1 + any apps specified in your kitchen (ROM), and subsequently installed apps (RAM) as well as just what it sounds like... storage for files etc (RAM).

The ROM is permanent and cannot be changed without reflashing the device (maybe with a special app, I haven't looked into it too deep... either way not something you want to do on a regular basis). The RAM you can change all day long easily.

So my question is why would someone want to include any programs in the kitchen builder to be included into the ROM? If they could just as easily be added later (as RAM) so that the programs are nonpermanent and can be deleted in the future if the situation came up? Is there some speed benefit to having the data on the ROM?