Ive read & re-read the posts on this thread & I cant understand what your problem with the back brake is!
Yamaha in their wisdom(they know a thing or two about bikes) decided to fit twin discs to the front wheel each with 4 piston opposed calipers and a single disc of a smaller diameter with two opposed piston caliper to the rear.
Its pretty obvious which brake does most of the work!...but there are times when you wouldnt want to use the front...just as there are occasions when its a good idea to use both together.
Unlike cars where one pedal controls the brakes on all 4 wheels-some using sophisticated pressure limiting devices to avoid lockup, bikes have two independent braking systems with very different physics involved.
So unless you buy a bike with ABS,TCS etc fitted as standard you just have to learn how to brake properly,safely& effectively.
Any talk of fitting old (possibly perished) hoses/inferior brake pads tells me you need to practice finesse with your technique. Theres absolutely nothing wrong with the standard set up which can only be improved by fitting braided hoses(rubber hoses have a limited life span) and it doesnt matter what you do/spend on your bike it wont make you a better rider. Only practice/training will do that.
The last thing anyone wants is some nagging doubt about the condition of the brake systems especially under emergency braking conditions. A locked wheel is a useless wheel so as said by others examine your technique and practice. Many novices fail to appreciate how hard you can actually brake UNDER FULL CONTROL!