Why would abolishing the Federal income tax be a bad idea?

With all the other taxes we pay, the government would have no shortage of funds coming in.
Abolishing the income tax would be the ultimate stimulus, putting the money back into the hands of the people, which would be able to go towards buying goods and services, which would funnel money back into businesses, creating jobs and profits, which will bring the economy in good standing again.
Why is this a bad idea and why are so many people against it?

I wouldnt need to borrow money from a bank, that we give money to if I could save $2000 a month in income tax.