Removing the corner bead has a chance at damaging the silicone between the glass. If the tank was built correctly it was put in at the same time as the silicone between the glass. If that is the case it will all be one piece of silicone. Cutting out the corner piece will just further damage the silicone between the glass.
As for the difference, it isn't what I think, it is what I know. I'm sorry you've never taken the time to learn the physics behind it, but I'm not lying to you when I say the corner bead doesn't do a thing towards holding the tank together. If it did 99% as you said, why do people bother to put it in there? Think about it this way, skip the silicone between the glass and if the tank were to flex it would pull your corners apart. If you add the silicone between the glass it keeps the corners together. And yes, that narrow bead that is only as wide as the glass is completely what holds the tank together which is why you want to us a quality silicone that is an adhesive, not a sealant. Consider this, if you were building a box out of wood and wood glue, where exactly would you put the glue? Sure, some may squeeze out from between the wood when you push it together but you certainly would not just put it into the corners and expect it to hold, it would be the glue where the two pieces of wood meet up. Same deal with an aquarium. It is the silicone between the glass doing all of the work.
And no, you didn't mention using GE brand, however several other people in this thread have. Way too many people use GE, it is a matter of time before people learn from their mistakes.