I'm really not sure why people are so disappointed, being honest. The anticipation built up a bit, but I don't remember ever being promised anything more than "a spaceport with an FSD". I mean, what else were you expecting? The Death Star?
They're a way-past-end-game item that SHOULD be hard to get (in the face of "Get a 'conda in your first week!") guides. They're expensive enough that you have to have a little dedication to get one, but not so expensive that you'll be mining or running passengers for months and months. And the upkeep is exactly to limit how many a person wants to keep up and running at the same time: this stuff SHOULD be expensive.
To put this in context, I'm one of the laziest, least-grindy people in the black, but I made a bil in a week when I put my mind to it (in a python, no less). I am not finding the cost (purchase or upkeep) outrageous at all - especially if you fly in a regular wing or are prepared to park up along a regular route and offer the use of your carrier to passers by via the forums or social media or whatever clever system someone will come up with to make these things a public resource (the Rats are working on it).
We were never promised a new class of ship. I think it's interesting that you get to tinker with the support modules you can equip, and (I suspect) perhaps they'll add more functionality over time as they see how people are interacting with and using them.
But a spaceport with an FSD is exactly what I've been expecting all this time, and I'm not disappointed in the slightest with any aspect of this so far.