Of course big corporations would rather not be obliged by the GPL. But my feeling is that, if we give them the option to grab the code without contributing back

Of course big corporations would rather not be obliged by the GPL. But my feeling is that, if we give them the option to grab the code without contributing back their improvements, they would just do that. In the long run, this risks harming the OSS community, as developers would feel like big corps are being leeches and profiting out of their work without giving anything back. After all, the GPL forces to contribute back only if you modify and distribute a modified version of the software (the AGPL modified this point, to account for cloud services). A corporation that isn't modifying GPL'd code or isn't redistributing the modified binaries, doesn't incur any additional burden for using a software distributed under the GPL.