They AI doesn't pick good locations for SBs, doesn't strategically select its SB upgrades, and doesn't use those upgrades properly to make use of SB's in stars or uncolonizables...
I mean, putting RB in the middle of a wormhole would be excellent...but the AI probably won't place it in the center, and even if they did, they'll only use RB when the SB reaches critical damage...putting a factory SB at a star is very useful, except that the AI won't be smart enough to always pick that upgrade...and even if they did, good chance they wouldn't necessarily prioritize that location for building frigates...
Point being, the AI needs to know how to properly use SBs first...otherwise, simply being programmed to place SBs at Stars and uncolonizables isn't going to accomplish much...