I got 4/5 unconditional offers (even though they weren't highly ranked universities). They say its suppose to help reduce the stress/pressure but I still pushed myself to work hard to get good grades. It worked because I ended up getting D*D*D*
However, I do agree some people end up slacking on their work when they receive unconditional offers. E.g. some girls in my class worked well in year 12 so they got unconditional offers but then ended up slacking on work in year 13 and only aimed for passes in their coursework.
I do think they should reduced the amount of unconditional offers they're giving out.