That doesn't account for how many missiles there are. There were points where I tried sending in ships armed with nothing but point defence. All of the platforms targetted one ship and it was quickly destroyed. There were so many missiles flying in that they got through because the point defence was busy recharging.
I got bored of it pretty quickly though so I never took the time to integrate any advanced tactics.
Maybe it's a difference between vanilla Sword of the Stars and the later Born of Blood (and A Murder of Crows) expansions? All I can say is defense satellites, when I run into them, are only a nuisance.
I had a fleet that was 3 normal (not shield, not point defense only) cruisers interdicting a developed world. One cruiser didn't have a drive anymore (which is one of the reasons they I didn't have them leave). Instead of abandoning it, I sent a repair ship that direction which was going to take about 9 turns. They just hung out at the edge of the system and destroyed missiles until the repair ship showed up.
Generally I take along a few destroyers armed with lasers/phasers/PD/whatever-I-have to act as missile defense when attacking a colony while my cruisers take along larger weaponry because if you don't take anything to combat missiles, yes they can be a problem. Usually then I destroy all or most of the defense sats (manually targetting them). Still, I rarely run into a world with more than 5 small and 5 medium sats. I could see coming up on a planet with a full complement including the largest taking awhile to pound through.
If I didn't like to play out the battles, though, there's no question in my mind that GC2 is the game to pick. On the other hand, if you want weapon placement/ship design to matter beyond rock/paper/scissors then SotS is great
For me, they fulfill different gaming itches so I like 'em both.