A few thoughts... I haven't voted because I'm not sure where I fall.
I agree on the logistical burden and lack of awareness/channeling to avenues of approach that come with wheeled or tracked vehicles. But they do have the advantage of giving significant carrying capacity, which I think is of vital importance.
Simply, moving on foot really limits what you can carry. I'm sure many of us have gone backpacking; once you get beyond about a week's worth of food your pack gets too heavy to manage, and that's without a rifle, ammunition, grenades, night vision, radios, binos, a helmet, flak jacket etc. and with purpose-built backpacking gear. With heavier (and more durable) mil-spec gear the weight goes up and the amount of food you can transport goes down.
Medieval military leaders discovered the limitations of horses for strategic mobility... again, after a few days from home base the need to move fodder forward takes up all your horses' carrying capacity. Their solution was pillaging, which is an all-too T2k approach to things!
Here's an interesting piece about the Vietnamese use of bikes... they modified them to carry up to 200 kilos of supplies. I'm leaning this way, except to note that anyone pushing 200 kilos on a bike isn't going to have a whole lot of energy to leap into action at the first sign of enemy activity.