The rule was not brought about because "it sounded good". It was found in testing by SFI that the belts and/or the thread used deteriorated with age and no longer passed the stress loads required to pass the SFI certification at some point in time.

So unless the seat belt manufacturers can develop a seat belt which will pass the tests for 5 years, and submit them to SFI, you can sign all the petitions you want and it will not change the rule.