Having ballista targeting be more player friendly (not the 'aiming reticle wants to touch your face' kind of friendly) wouldn't invalidate all other base defense options though.
If anything it makes it reasonable to use.

I get not arguing for changes to improve them, if you don't want them don't use them but I don't get why people argue against it. They're simply not reasonable right now.

I know that even if they didn't target players I would hesitate using them myself because the constant drain on ammo is something I'd dread but I'd at least consider them.
Sure I'll build some for aesthetic reasons but that can't be their actual purpose...