Not getting into how long is too long, but for comparison...
The walk from DHS hub to what will be the furthest bus stop is .54 miles.
That's the same distance from the Epcot fountain to its furthest bus stop.
Which is the same distance from Tusker House to the furthest bus stop.
Which is the same distance from the Tea Cups to the furthest bus stop.
However, for the MK, that's the furthest Disney resort stop, if you're going to a non-Disney bus, you have to go through the monorail or ferry greatly extending the time to get to the bus.