Mandatory voting

[Dystopia]

I'm against mandatory voting - In my opinion it is the duty of a concerned citizen to vote at least as a blank vote if you're against the system, however I don't think coercion is the answer - I do think abstention is troublesome specially in Europe, but mandatory voting is not the answer. Brazil is an example of mandatory voting. One of the main arguments, in my opinion, against mandatory voting is that ignorant people who aren't concerned with the system will inevitably vote poorly and sometimes extremist parties gain votes

If it is the duty of a concerned citizen to vote then why shouldn't it be mandatory?

I've already said the ballots should have a none option, but I'll take that a step further. If the nones end up with a majority of the vote then why not disqualify the current candidates and have another election?

I distinguish between civic duties and legal duties - The latter are the ones you should do because the law says so, such as not killing or raping, the former are duties that, in my opinion, people should exercise but not coerced.

The only argument I can think of that is valid is the following - Sometimes a lot of people don't vote, and as a result (at least it happens in Europe) politicians are elected by 40-50% of the population, and since everyone votes for different parties some politicians only have the support of 20-25% of the population - This violates the principle of democracy because in theory the majority didn't vote for the current government.

I'm just trying to lay out the pros and cons, but why do you think specifically that it should be mandatory - What benefits do you see?