The GPL, unlike the MIT license, protects against people adding a small thing to an open-source program that might become necessary to use it - thus taking it out of being usable in its open-source form. So the GPL is a good thing.
This is completely untrue. Anything that's MIT/BSD/Apache licensed keeps stays that way when code is contributed to it. What those licences don't try and enforce is whether somebody tries to embed the code in a proprietary product. This means more coding, less lawyering.