Stargates

I've been thinking a lot about stargates recently. CCP's famous (or infamous depending on your point of view) image implies that at some point we will be able to build stargates.

With Crius the first arrow in that diagram has been mostly dealt with so we are getting closer.

However, I'm plagued with question less about the "Stargate construction & control" which will be years out still and we need to see how the other 3 sections pan out, but rather asking questions about why we are where we are now. In other words, why can players build (and destroy) stargates now?

I know the simple answer: because such a feature has not been implemented in game yet. And I know the more philosophical answer: because that much control to players could lead to unbalanced power equations and stale min-maxed game play (e.g. imagine every staging system was a dead end system with a single perma-camped and bubbled gate).

But what's the lore reason? I mean, its obvious that player alliances in null space are a power comparable to the major empires, they have basically urbanized most of null sec with outposts, jump bridge networks, cynosaural beacons and jammers. Yet slightly larger construction efforts like true station building and stargates have remained out of reach. Why?

The best possible answer I've come up with is that its more beneficial to the null sec alliances to NOT build such structures. Specifically, the protections all capsuleers enjoy due to the CONCORD agreements the empires signed have large benefits (such as freedom of movement between empires, freedom to dock anywhere, protection from asset seizures, not extradition to planetary governments, etc) that outweigh losing them for stations and new stargates (or destroying existing ones).

Although many null sec players live almost exclusively in null sec, their associated alt characters and business ventures rely heavily on empire resources and markets. Imagine what would happen to a null sec alliance if it was completely cut off from Jita's markets all of a sudden. So that seems like the most likely culprit.

Another possibility is that there is no other known places to build stargates, i.e. the current possible stargate network covers all possible locations. This seems unlikely and is easily contradicted by stargate connection changes in past expansions.

A third possibility is that the technology is tightly controlled by the empires. Again, seems very unlikely since null sec alliances have the jump drive tech and stargates use the same basic principles just  on a larger scale.

Perhaps the problem is simply cost. Maybe stations and stargates are so expensive to build that its out of reach for null sec alliance wallets. *Looks at massive titan fleet* Yeah, I don't think so. Unless the problem is not cost but rarity, perhaps both stations and stargates require some ultra rare material in their construction and thus this rarity limits their propagation.

Any thoughts?