To me, Dulinor is a tragic figure first and foremost. He had ideals, very high ideals, and a genuine desire to improve the life of the avarage Imperial citizen. But he could not break away from his heritage, from his Noble upbringing, from the tempting and corrupting power of his post as High Noble. He fought against the inherent injustice of aristocratic rule, but he fought as an aristocrat, using the methods of the aristocracy.
And where do we see the influence of his Noble birth over his actions?
1) Faced with conservative Noble opposition to his reforms, he could have appealed to the masses, he could have relied on the people in his struggle against the aristocracy; in other words, he could have tried to rally the masses to his banner and declare independence for Ilelish against the Imperium. But he didn't. Instead, he tried to change things using "ordinary channels", to completely ignore the people he fought for and instead try to resolve this conflict in the traditional way of Nobles - that is, attempting to take the Throne by the right of assasination.
2) Once in power in Ilelish (after killing Strephon, that is), he could have conceded many of his powers to the people (that is, to elected bodies), he could have abdicted and call for the creation of a parliament in his place. But he didn't. He could not part with his power; he continued to rule his faction more or less in the autocratic manner to which he was used. The few reforms he've passed were given from "above"; and his administration remained a monarchy and run in an autocratic way - hell, he even had no problems with his brother being his chief admiral.
3) When the war got prolonged he could have listened to the people and try to sign a cease-fire with Lucan, or, atleast, concentrate more on defense and not waste taxpayer money on his Inaguration Fleet. When the Verge Combine seceded, this couldn't be too clear. Instead, he ignored the pressure from below and stuck to his own goals.
4) Dulinor's regime grew more and more opressive as the war went badly and he was afraid of losing control; he crushed any opposition and any dissenting voice, quite contrary to what was (probably) his original ideal of democracy. He became much like the system he fought, first and foremost because he was part of that system, belonged to it lock, stock and barrel.
Some people could break with their heritage and upbringing; but this is a difficult task. In that task Dulinor has failed.
Another aspect of this tragedy is the fact that he was trying to revive an Imperium which was already dead from inside, or very close to death; and, worse, he was trying to change it from within the system while knowing (to some degree or another) that the system was rotten in its core. The economical engine of the Imperium, which was interstellar expansion and colonization, was long dead; and with constant borders things began to stagnate. The Imperial system was no longer doing its job - nobles were in many cases nothing but petty schemers out to maximize their own profits (political and economic), megacorps were monopolistic and monolithic monstrosities of bureaucracy, and all the strengths of the Imperial system were turning into weaknesses. It was not the time to reform the system; it was high time to replace it. Neither Strephon nor Dulinor nor Norris could fully grasp this, but Dulinor's errors were the most tragic, especially since he came so close to the truth, only to turn back and return to being part of that dying system.
