The clones just sit right in the open on the AT-RTs...there's not much armor anywhere. Head is open for a shot, and a good portion of the chest is, too. Why not have a windshield or something to protect the face?
There's a fair number of military vehicles today with light or no armor. AT-RTs appear to be all about speed, especially on TCW.
They are pretty useless in games such as Battlefront. Open cockpit is a sniper's delight. I could see this occurring in the GFFA too. If you compare, TCW showcases it differently than what the game mechanics of BF show.
But you never see blaster bolts penetrating the clear armor around, let's say, an AT-AT command head...
You can easily shoot people on a speeder bike, as demonstrated in ROTJ (and ROTS, as mentioned above), so they are sitting ducks. But that's not my point; the point was, why don't speeder bikes "have a windshield or something to protect the face"?
I think the heart of the matter is no small, fast attack vehicle is going to withstand much of anything. Windshield, or no windshield, you get hit on one of those? That's all she wrote, unless your name is L. Skywalker.
The AT-RT really does appear to be a redundant vehicle when one considers the speeder bike. The only use for it I can imagine is when one wants speed, but not the insane amount of speed which comes with a bike.
Well, then again, if you watch TCW you'll see that AT-RTs can actually jump pretty far/high. IDK if a speeder bike or any type of speeder can go over large crevices or obstacles...