There is a perfectly good guide about it on this very forum clickety so I see no reasaon - jailbreaking is something you only need to do once, so why should it require a fancy GUI?
Furthermore, it's not apple's fault that open source developers haven't done something that explicitly does what you want - open source is about satisfying the developer's needs first,.
If you don't enjoy what is offered you are free to develop it further - in this case you are more than welcome to develop a GUI front end, it's not particularly hard.