Why should I root my android phone?

There are lots of reasons why people do root their android phone some just for the fun of it and others to solve a limitation. Below are some of the limitations that can be scaled through android rooting.
Rooting enables you to remove any app that was preinstalled on your phone by your phone maker. Rather than simply disabling these bloatware titles, which is often the most you can do within Android, rooting can grant you a full uninstallation. This could be useful in freeing up additional storage capacity.
Another important reason for rooting you android phone is to be able to flash a custom ROM. “Custom rom” is a custom version of Android, and it truly changes how you use your phone. It could take some time for a new version of android to get to our device but once rooted, you can often get some of the new platform features through custom ROMs in short order. This could, for some users, add years of life to an Android phone. Rather than buy a new phone, flash a new ROM.
Another reason why you could root your phone, is to be able to flash it with a custom kernel. Some android tweaks require a custom kernel which you can only flash with a rooted android device. The kernel helps the apps in your phone communicate more effectively with the hardware of your phone. A custom kernel can improve the phones overall performance, battery life, and can even add extra features like Wi-Fi tethering on unsupported phones.
Another very good reason to root your phone is to be able to do a full backup. When your switching to another android device or for any reason want to restore your device to stock, you can make your life a lot easier by backing up your apps and settings first. That way, you can get your entire setup back in just a few taps. If your phone is not rooted, you can back up a few things like apps and data but won’t be able to back up system apps and data, or automate the entire process as well as titanium back up can. Titanium back up is not only used for backups, it can also uninstall those annoying battery-draining, space wasting crapware that comes preinstalled on so many phones these days. This features only work on rooted devices.
Other reasons of rooting could include being able to install apps that are not incompatible with your phone, removing adds from apps, boost your device speed and battery life, etc.


Why you shouldn't root your phone

Rooting a device can void your warrant. Some manufacturers or carriers will use rooting as an excuse to void your warranty. It’s worth keeping in mind that you can always unroot. If you need to send the device back for repair, simply flash the original backup ROM you made and no one will ever know that it was rooted.
Rooting a device can also lead to the risk of bricking the device. This is the big fear that everyone has else you might end up turning your device to a “glorified paper weight”. The obvious way to avoid that is by exercising caution when attempting to root your phone and pay close attention to whatever you're doing. Make sure that the guide you are following works for your device and that any custom ROM you flash is designed specifically for it. If you do your research and pay attention to feedback from others, bricking should never occur.
Finally rooting may introduce some security risks. Depending on what services or apps you use on your device, rooting could create a security vulnerability. For example, Google refuses to support the Google Wallet service for rooted devices.


source: (http://techvarsity..com/2013/08/android-rooting-deep-truth.html)

If you bricked your phone flash it with a stock rom of the phone & if you are in need of stock roms of phones like Tecno, Gionee, Lenovo etc go to http://amparasroms..com
tutorials on how to flash the stock roms on the phones are also available on the blog.