It's weird how people think navigating through undeveloped land is like walking across a parking lot. Brush, branches, thorns, downed trees, uneven ground, etc can make walking through undeveloped land difficult to impossible.
Really depends on the land in question. Some forests have thick underbrush, some are almost completely clear. A lot of undeveloped land isn't even forest - swamp, desert, rocky mountains. Sometimes it's far easier to navigate than a parking lot, IME.