Yes I get that you are only referring to airsoft.
Just about any other person here sees a step like that as a reasonable requirement to gain access to airsoft rifles etc. With the hope that with legitimacy will come wider access and after that pricing in line with other countries.
The public will see it as Cheap US assault rifle copies flooding across the border and so on.
The counter argument of it's already happening so it should be regulated for safety is checkmated with it's already against the law and any underground gun trade must be stamped out.
The public at large and the Government along with enforcement don't see any reason why someone needs these. Countering with "but I like it", and "I promise not to shoot my eye out" doesn't hold weight when you're trying to pass something like this through Parliament.