In Jumpgate, the Tow was the standard heavy cargo ship. I remember a guy called Ridgeway who ran one of the major player factions who never got out of his Tow because it was so potent, defensively speaking. Being able to shoot him down, or even seeing him shot down, was a rarity and point of pride among his opponents. The amount of firepower I saw thrown at him time and time again, only to have him kill a couple of stragglers and escape was comical. When I was eventually put on his group's KoS list for trespassing (or some other nonsense reason), I knew a direct confrontation was hopeless, so I just bought a cargo ship of my own, took out a loan (from another player group I was aligned with) equal to about fifty times the credits I was ever going to make (I never planned on being able to pay them back, and I'm pretty sure they immediately forgot they'd given me money anyway) then in the dead of night, snuck into the station Ridgeway's group had claimed, and stripped it (buying all the stock then selling it at a loss to hostile stations...a grievous offense in a system where all inventories were player made and transported). It bankrupted me, took a harrowing half dozen trips to accomplish (the last few, after I was detected, greatly aided by the speed and durability of my Tow), and meant that I had to spend the next year almost exclusively in the second fastest ship in the game (a largely untouchable ranger, which had limited defense and firepower, but amazing sensors and speed) looking over my shoulder everywhere I went (docking under fire is always dangerous)...but it was so worth it. They never did mange to shoot me down, though I got a few of them by surprise, when opportunities presented themselves.
Anyway, I don't think most PvPers would have a problem with difficult targets (and even ED is an example of this...my CMDR has been engaged countless times, not because it was easy, but because his opponents knew he could run and, if need be, fight), and I think many, if not most, of them relish being the underdog...as long as everyone is playing by the same rules. Of course, playing by the same rules gives groups an edge (organization is OP) over individuals in most areas (but not all), and means skill matters (though too narrow an applicable skill set can also be boring, just ask CQC or the TC plasma FDL 'meta').
Also, the distinction between offensive and defensive weapons is an arbitrary one. Systems that make such a distinction, and actively prohibit off-label uses, are blatantly absurd and usually not fun, IMO.
