Traditionally and ideally, Homebuyers go to the bank with 20% deposit. With 4 bedroom homes costing $1 Million these days, that's $200k. People don't have $200k, that's a problem to be sure.
The proposed solution is to help people who have saved $20k to get into the market. I like that the government is trying to help people get into the market.
I would prefer solutions that lead to houses being cheaper. This solution won't do that. In fact, by making it easier to buy a house at present prices, the government is increasing demand - and therefore house prices. What if instead of increasing demand, the government increased supply? I'm no economist, but if the supply of a product raises to meet demand, prices for that product fall.