Rooting your Android phone is good for you and your phone
Android rooting is largely beneficial to the user because it unlocks the phone to the consumer so that they can freely modify the software on it in its entirety. Android already allows a user to install software not on the market already (Settings > Applications > "Install Third Party Software" checkbox), unlike the iPhone. Many Android users that root often flash a custom ROM like CyanogenMod or some kind of modified ROM of the stock ROM of their phone to increase performance, tweak it how they want, or simply use a system that promotes the open source software philosophy. Other uses for rooting are backing up installed applications, backing up data (wifi spots, mail, texts, MMSes, etc.), over/underclocking your phones CPU, hacking the Android OS, flashing a kernel that provides performance/battery life benefits, and a myriad of other uses depending on person. According to law, it is no longer illegal to jailbreak/root your devices but it does still void the warranty o