Can't see that actual petition having much impact but I'm pretty sure the government here will bring licensing in at some point for 2 reasons.
1 its an earner from those that do apply
2 its an easy prosecution for those that don't. If for any reason a copper comes across an airgunner and they have no licence - game over. If a house is searched for whatever reason and unlicensed airguns are found, regardless of the reason for search - also game over.
If folk don't want to apply for licences that's their choice but they know the risks.
Licensing airguns will not prevent any crime.
Unfortunately anyone not having a license is taking a big risk