If I change the sentence to: "Most companies these days just go all out to make a quick profit." it still doesn't have the same meaning as "Most companies these days are just out to make a quick profit."?
To go all out to make a quick profit means to make every effort towards that goal. To be just out to make a quick profit means that is their only intention -- it doesn't mean they have to go all out (expend a lot of effort): they may have found a fairly effortless way to take your money.
They are close in meaning, especially with a quick reading, but they are not the same to me.