[Psitticine]

Even the larger sats lack the space to hold all the components available to ships at higher tech levels. They also can't mount the larger Versions of weaponry, which are much more effecient in terms of space/damage than their smaller brothers.

Probably the most important drawback though is their lack of mobility. Who cares about the satellites if you can just circle the planet and waste it from the other side? Let the sats carry on guarding the ruins if they want!

That same lack of mobility makes them pretty useless for guarding warp points as well, although they can be used to bolster other guardian forces. Unless the enemy forces at a warp point can force you to close with them, you can click End Turn 30 times and proceed on past.

BTW, here's a tactical tip for fighting against satellites. I've not heard much about the use of repulser beams, but they are marvelous for knocking those sats away from the planet they're protecting. If you pack enough PD cannon, armour and/or shields onto a ship so it can close with the sats, a repulser can shove them right out of their useful range. Oh, and an emergency booster is a great addition to a ship design like that which needs to close as quick as possible!