As Locklave said, and not just the major factions, but also the Indies and pirates. In other words, only the player is penalized for sat bombing a planet, and stinks of the "Gang Up on the Human" trope.
Also, if major factions that are supposed to be friendly or cooperative send gigantic war fleets over and over and over again in so-called expeditions, eventually, the player who gets sick of it may just scream "ENOUGH!" and crush the attackers at the source. Unfortunately, the only way to do so is to destroy their planets, which means either sat bombs or decivilization from prolonged zero stability.
There comes a point when the factions should stop treating the player like an insignificant upstart and more like a superpower stronger than all of the core worlds combined, especially after the player wipes a couple major factions off the map for their insolence.
That said, I have no problem with other major factions getting mad over a sat bomb. They are big enough to take sides or act on their own. It is the Indies I have a problem with because they look like a small neutral faction who are not big or strong enough to be major players. If Indies get mad just because I sat bomb a major faction that would not stop their unprovoked attacks, the message I get is the Indies are a puppet state that joined with their masters from the major faction, and they become a valid target to eliminate too because they got in the way and/or providing aid to the enemy.
P.S. They all get mad if I sat bomb a pirate planet or space station in the core worlds, but they are A-okay with player destroying a pop-up space station in the fringe.