Like you, Joshua, I used to cook custom roms on android, rather than WP. To me, rooting was a MUST if you wanted to use your device to it's full potential. It even extended the life of older devices, where the manufacturer had ceased support.
It was NEVER about 'stealing' someone's intellectual properties. Manufacturers include so much junk that your device was hampered. Rooting allows use of apps like apps2sd to ditch this bloat, it allows Xposed framework to be run allowing full customisation of a device. Adblock was a godsend, and sped up browsers no end
It allowed rom cookers to install custom recoveries, which opened up more avenues, and allowed flashing, resetting and installation of roms, a piece of cake. Now we could tinker with kernels, which once again, allowed improvements in phone operation and battery usage, along with throttling of the CPU speed, or if you were brave, crank it right up. Lionheart was one of my faves, as it gave a good compromise.
Finally, you could have a rom that you could customise to your hearts content, be that pure stock, or a lunatic fully ported one! My finest hour was a note 3 running a note 4 rom with S6 components built in!
So there you go. Rooting / Jailbreaking doesn't mean theft. It allows under the hood improvements, and allows your device to be yours, and could lead to porting apps easier for the home tinkerer.