No. As other comments here state, the difference between Present Simple and Present Continuous is actually very important here. Let me copy my other comment:
Our approach in this course is as follows:
to go, to walk (generally, habitually) = chodzić
to be going, to be walking (right now) = iść
to be walking (but without a purpose or direction, just walking around) = chodzić
Oh, and you have to take into consideration that 'chodzić' is generally on foot (although it can mean 'to attend', in a way), so there will be other translations if you use a car, for example. And so is the case with "iść", it's also on foot.
Because "iść" is walk/go right now in a specific direction. while chodzić is walk/go usually or without a specific direction
The best way to translate this difference, and the way duolingo enforces is to say:
They walk= oni/one chodzą
they are walking=oni/one idą
it's not perfect, as there are some circumstances where the line is blurred, but it makes discinction clear.