Additional Info Mods Question

[turkwinif]

My question is based around mods like KER and MechJeb, mods that show information on your ship, your orbit, your Delta-v, etc.

What I was wondering was, why do additional info mods require you to place one of their parts (MechJeb: strap a calculator on; KER: Placing a walkie-talkie like device) on a ship in order to access the GUI? Why can't the GUI just be there to begin with? This question is out of curiosity.

EDIT: Whoops, didn't even know this sub-forum existed. Thanks mod!

EDITEDIT: Alright, thanks blizzy, changing to answered.

EDITEDITEDIT: Just remembered what sub-forum I'm in

Edited May 1, 2014 by turkwinif

[Vanamonde]

Mod question moved to the mods sub-forum.

[Red Iron Crown]

I think it's to give you the option of playing without them easily if you so desire. There are mods to add them to all pods without adding parts.

[blizzy78]

Some of those mods were made in the times where having a part (and associated plugin code) was the only way to get into the system. Nowadays there is no need for parts anymore, but those plugins have not been changed. Which is to say, KER and MJ could both be partless plugins.