Everyone realises that the Government Discussion Paper is not just dealing with EVs, but people are questioning whether it would have been better to give higher discounts to people who buy EVs, rather than reducing the overall amount available for EVs by giving discounts for the purchase of some lower emitting petrol vehicles.
Before the release of the Discussion Paper, I don't think anybody suggested that, in the fight against climate change, purchase discounts should be given to buyers of new lower emitting petrol vehicles. This could possibly show that the Government doesn't see the elimination of petrol vehicles from our roads as a high priority in the fight against climate change.
I personally would have preferred that no vehicle that emits emissions received a subsidy and at best had no levy (ie. their position doesn't change). However, the proposed scheme does reduce what qualifies for a subsidy each year, eventually getting to the point where even hybrids receive no subsidy.