(although it had no serious problems at the time)
Though I don't think they were the whole reason for the concept of Ferrium, the SCP definitely had some big problems back then.

The Y-targetting crash, trying to simultaneously support D3D and OGL, multi-docking, autopilot, in-mission cutscenes and normal maps were mere dreams, no correctly working multiplayer, faulty/inefficient/incomplete shadow, decal, submodel animation and material systems, only the first stages of scripting builds if they were actually out back then at all, some very troublesome FRED build problems that IIRC prevented all but one person being able to build it, all kinds of sound issues (that have since been cleaned up via using openAL), no FSO installer to help newbies, faulty MVPs, and a few other things like shinemaps not working on certain cards.
Kazan I think already had Ferrium in mind before that period, but those problems are certainly a part of the reason Ferrium generated so much excitement. Since then though thanks to the hard work of all the coders on the team, the SCP has not only rid itself of those bugs but has come leaps and bounds in terms of graphical abilities and overall feature sets.
