I'm on the fence about this one. Getting more people to vote is great . . . but not if they're forced to vote. If someone's forced to vote, why wouldn't they get upset and angrily vote for the worst candidate because they hate the system?
First you have to define what you mean by "worst candidate", only then can we tell you if that happens in Australia.
If you mean some nutter with extremist (right or left) views, these get 2-10% of the vote typically. If they start in a major party, do a reasonable job of representing their particular electorate or state, and then defect to their own nutter party, they may sometimes get a single term from sheer momentum, but typically they're gone after that. It's not clear that people are voting for them out of spite at having to vote, when polled you'll find 2-10% of people support various extreme policies.
Because we have the secret ballot, nobody can actually make you
vote. You can go in, get your name ticked off, take your ballot papers, and dump them blank into the ballot box - or write obscenities on the paper, or whatever you like. Typically this runs to not more than a few percent of the electorate, it's not clear how often it's deliberate, and how often it's someone with dementia in a nursing home, an older migrant who doesn't speak English, a newer migrant or younger person who doesn't really understand the system and doesn't read the instructions (putting "X" by their favoured candidate rather than doing the 1,2,3 etc of preferences), and so on.
We have polling days on a Saturday, mobile polling booths (there was even one in our Antarctic base last time), generous provisions for pre-polling-day voting (we voted early to avoid the crowds), and so on. In every election there are a few percent of eligible people who are not registered to vote, generally those who turned 18 since the last election, who've been overseas for several years and only just returned, and so on. And there are another few percent of "informal" votes - blank, marked wrongly, etc. But we generally achieve around 90% participation.
Combine that with the AEC drawing up electoral boundaries and thus nixing gerrymandering, and most people have their say.
Of course we still have various kinds of corruption in political affairs. But we don't disenfranchise large chunks of our citizenry, so this helps minimise the corruption.