Budget? You mean the savings documents the L/NP released prior to the election? (note: not a budget)
A lot of the rage is because a lot of the "savings" are inaccurate in places. For instance, there's $450m in savings from cutting the CEFC, when in fact in the short term they'd save somewhere in the order of $18m from disbanding the CEFC, and in the long term they'd lose significant amounts of money (since the CEFC acts as a bank, and makes a profit).
There's $1.1b from reduced equity payments to NBNCo, when in fact spending on the NBN will rise short-term (because of contract renegotiations). There's significantly reduced ICT research funding (around $45m, iirc).
There's the $5.2b expected from cutting the public sector by 12,000 workers, when this is only expected to save around $2.4-2.6b, and only under absolutely optimal conditions (which these are not). There's only 4 years funded for the Gonski reforms (6 under the ALP), in which the last 2 years was supposed to provide 80% of the funding - some $8b.
There's significant investment in road infrastructure, completely removing any funding for rail infrastructure - at a point in time when public transport systems (rail and bus) are seriously stressed in certain cities, and road spending tends to increase congestion (not decrease it). This is particularly noticeable in Perth, where people in outer suburbs such as Ellenbrook have been promised a rail connection for the last 6 years by the state Liberal government (taking the promise to two different elections), and are now s.o.l. because 50% federal funding was required for the project to go ahead, which has now been removed.
There's also the wind-back of a number of income tax cuts related to the carbon tax, which are likely to go along with it: notably, the tax free threshold (currently $18,200), set to go back to $6,000. The schoolkids bonus, which was something like $600 per child for poor families whose kids are in school, to pay for books, uniforms and equipment. The low-income super co-contribution - which allowed even the poorest to put away their meagre savings for the future, and the government would (to a point) chip in an equal amount for every optional contribution - has been removed, in favour of middle-class welfare in the PPLS.
The total savings brought by these measures were something in the order of $6b over the ALP's budget. This isn't $6b for the next year, with more to come: this is $6b in savings over the forward estimates, of 4 years. We're cutting assistance to the poorest families in the community just so we can "cut the carbon tax", "stop the boats" and provide Paid Parental Leave to everyone, for the sake of SIX BILLION DOLLARS OVER FOUR YEARS. We're destroying what is possibly one of the most important infrastructure projects in the nation's history - the NBN - and we're doing so by removing the one thing that provided the nation's largest drop in carbon dioxide emissions in history, the carbon tax. All for a 1.6% reduction in spending over 4 years. It is a thoroughly fucking shitty situation, and it's really sad to see.