I loved this mission for all the reasons that you have stated. The first time I played it, I got to 9 hours and basically broke the game! It kept crashing back to desktop. It was annoying as I'd almost completed the mission.
I posted on TTLG about the crashing and Nicked suggested it may be something to do with memory leakage as I was taking so long. As I have no idea about dromed and the creation of missions, I took his word for it. Someone else posted that they'd played for a simil...
Yeah this is a dilemma I try to personally circumvent by basically giving all demos a "5" regardless of how impressive or unimpressive they might seem. Maybe we shouldn't be able to rate demos at all on TG? I'd wager that a lot of demos have a pretty wide spread of rating since some people want to slam down a "1" for a poorly made mission and others look behind the curtain and give it a 7 or 8 for the ingenuity of the technique that is shown.
I haven't played through that mission so can't compare.
But on a general note as I suspect this is some kind of a catch question of the "why water is wet" type I guess there are some scenarios where a lack of objectives actually helps immersion and would be preferable to a classic "normal fm" setup - I'd say an example would be where the player's avatar's identity and whereabouts are unclear and exploration of the unknown in itself is more than enough of a goal - a classic example always ...
What makes a lack of objectives a bad thing? Malazar has like one.
I might continue Rocksbourg. I am at the Keeper hideout in mission 2. The people having French voice lines kind of breaks my immersion a lot. The corridors begin to blend together a lot and I know that mission 3 takes place in this base completely. It doesn't really excite me, sadly. For its time it was incredible and unique. That I can see. Maybe I'll be amazed when done with mission 3, so it's probably still worth continuing.