Then why did they put them in the reach of individual players then?
Irrespective of that, it’s not just individuals losing out. Corps of 50+ players (who built their expensive structures from blueprints by grinding the mining/PI/manufacturing required) are losing their structures because CCP chose to make structure kills a guaranteed loot event.
We wanted to defend - but there was just no way we could. Sure, we could have put up a fleet today - but then the attackers just come back tomorrow for the guaranteed pay-day. My biggest peeve with Quantum Cores is that players who simply played by the rules CCP had in place got done - they had to spend more money just to maintain a status quo in terms of services whilst at the same time having a large target painted on their structures - and they got NO benefit out of that at all.
Want proof that it’s the cores driving this? We had three structures in system - one with a core, two without (all pre-dated the Quantum Cores patch). The Fortizar was destroyed, the Athanor and Raitaru (necessary because of the fuel block consumption bonuses) were left untouched.
A big issue at present is that the structures are TOO specialised by design, and this mechanic causes a real need to create multiple structures just for basic widespread operation types. Not only do certain structure types get efficiencies around specific activities, they also get bonuses on fuel block usage, AND certain activities can only be done in specific types of structures (moon mining from refineries for example).
IMHO, what’s needed is either a new structure that can do multiple things (jack of all trades but master of none) or to grant the Citadels the ability to do all things (potentially at the same bonuses/efficiencies as the smaller specialised structures - an Azbel at Athanor/Raitaru levels, a Fortizar at Azbel/Tatara levels). Make it more expensive to start with, no worries - it’s more useful after all. This would reduce the prevalence of smaller structures (three structures could easily be condensed into one) but not cut back other capabilities in the game (the lack of player-owned structures in highsec is really impacting on clone usage, I am sure).
Alternatively, give NPC stations better capabilities (the clone jump delay is stupid anyway, just get rid of it already, make the infomorph skills that reduce the delay do something else so that the SP isn’t wasted, or just remove it and hand the SP back to be used elsewhere), and make the NPC stations more varied in their capabilities and bonuses). That’ll reduce the number of player-owned structures too.