>>64215617
Because that specific walker is essentially a recon vehicle that is also armed with a space equivalent Ma Deuce but also has some bullshit super-AP bullets it can use in a pinch to harm heavy armor so it can pull double duty as a weapons platform and support infantry pushes or use hit and run tactics against enemy armor in areas that said armor cannot pursue them effectively. Hoverbikes are strictly recon, their guns are pretty much useless for anything but trying to shoot at other recon vehicles in dramatic race scenes through hazardous areas like forests so you can get some sick explosions and wilheim screams, (an essential part of any Star Wars military), but are only really used to get from A to B and dismount.
tl;dr-
>Hoverbikes=dirtbikes, recon vehicles at best
>Chickenrunner=one of those dune buggies with a .50 on top but it only needs one operator