QUOTE
The SSM wasn't that good
I think it's one of the most important units Nod has since it can outrange Advanced Guard Towers (which would otherwise take many tanks or bikes to destroy). They're also fast and can easily escape if GDI sends an army of tanks after them (although AFAIK humvees catch them, so they need something to support them).
As Nod I usually build only a few normal rocket launchers because the SSM launcher can't shoot air units.
I agree that the Obelisk requirement makes no sense.. although I always build some Obelisks, so it doesn't affect gameplay.