OK let's be clear, every android device is different and none can become a brick by the act of rooting in itself.
When an android device is bricked, be it by hardware or firmware fault it is unrecoverable. Most of the time that someone says they bricked their phone it is just in a bootloop because they erased their os or did something they don't understand etc. But these are not bricks as they device is often easily recoverable.
Now there are times when it isn't, and not just due to a hardware fault but from firmware (bootloader, radio, etc) which may have been the wrong image flashed, or flashed to the wrong partition or incomplete, whatever. This can lead to a brick, but this isn't the act of rooting that bricked it it was a mistake made by the user
Some devices even have a special download mode of sorts that allow you to fix this without JTAG, in this case it isn't truly bricked either, rather they still can use a fail safe to fix it, often rather easily.
On one of my devices a long time back I was wanting to play around with my own custom bootloaders, but prior to this I sent the phone to adam Outler (as I was uncomfortable doing the ultra fine soldering myself) and with a hardware mod changed the boot sequence which if I hadn't done this, during my many failed attempts, I could not have even accessed the download mode to fix my brick
Some people will insist that they did nothing wrong while rooting yet still got a brick. But again all devices differ as does the root method, sometimes they mistype a dd command and flash a recovery image to the radio or whatever, this wasn't root or the act of rooting that bricked their phone, it was their carelessness, or at least not understanding what they are doing when they do a battery pull while flashing firmware.
Sorry for the rant but this question has been around since the g1 days and the answer is still unequivocally no, the act of rooting itself can not brick your phone.
Sent from my Nexus 4 using XDA Premium 4 mobile app