You need these restrictions in order to protect your freedom. If GPL would allow combining code in proprietary code, someone could take your GPL-code, build a product out of it, release it under a proprietary license, then sue you for infringing his license.
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You need these restrictions in order to protect your freedom. If GPL would allow combining code in proprietary code, someone could take your GPL-code, build a product out of it, release it under a proprietary license, then sue you for infringing his license.
If this was true wouldn't people releasing code under other licenses such as the LGPL be getting sued now?