But only if they stood a more than reasonably chance of defeating them, I guess?It's a valid point, and I also have no objection to some harsher penalties being given out in certain situations. But they need to be reasonable, and personally I don't think completely banning a player from a system for destroying another one would be reasonable. Of course, hurling system security vessels at said offender would be great.
For me it depends on the system. I know it sticks in some folks' collective craw, but I still believe there should be systems that are more or less 100% safe. Sol, Achenar, Alioth at least. A few regional historical capitals. Maybe some PowerPlay systems, so that maintaining control and making them safe for trade would become part of the gameplay. Starter spawn systems (maybe move them to somewhere safer rather than buffing the security of Eravate). Places where violence is met with instantaneous overwhelming force and/or a very long access ban via the permit system. Yes, the permit system is silly. Yes, instant overwhelming NPC force breaks the immersion a bit. But it's not as though the rest of the game is a paragon of verisimilitude.
The biggest problem with this is that the game offers nothing at the other extreme. There are anarchy / lawless systems galore, but there are no warlord-controlled, pirate-infested systems where bounties are badges of honour and a negative superpower reputation is a requirement for entry. And if there were, there are no in-game mechanics to encourage players to consider joining such a clan for anything other than external RP reasons. So I don't think introducing uber-safe systems in the absence of other changes is the answer either. At least not yet.
But I would eventually like to see these extremes in the game, along with all the variations in between. It's not as though the galaxy isn't big enough to support them. I'm sure Sandro said this was also FD's vision back in the day; if memory serves he used a modern city as an analogy, with reasonably safe places and generally shady places and places in between. I'd dig it out if I could find it but the search function is worse than useless at the moment, returning "no matches" for searches I know had hits last time.