You mean "because they want neither to be imprisoned for all eternity, nor to be subservient to a being they feel has betrayed them in favour of His 'younger children', ie. mankind".
The methods they have chosen, certainly, are not in the best interests of mankind, but then, they were here, first, and it wasn't the Fallen that set this course of action, but rather had a dichotomous ultimatum set for them. They just responded with 'option C'.
Well, you are welcome to such an interpretation, and I can certainly see such a view. I'm not using it myself, since the references I chose to use (which were primarily detailed scholarly analysis of Revelations, using other sections of the Bible to attempt to interpret those verses) don't mention jealousy. Basically, according to these texts, the angels were given direct dominion (as opposed to Satan's more ephemeral dominion) over mankind in God's name (twice!), they started doing whatever they wanted (twice!), and they had their positions revoked (twice!). I've basically chosen to not paint the Denarians in a sympathetic light (at least not as a group). It's a personal choice, because I
love the Denarians as bad guys, and I want them to be bad.
That being said, if you want to go the sympathetic route, I think you could get real mileage out of a Denarian who is seeking redemption, or simply regretful about the path that has to be taken to achieve their goals. Personally I think the "it's all God's fault cause he didn't love me enough!" tact has been done to death, though. Then again, my players (well, former players, my group recently suffered catastrophic failure) tend to be disturbingly savvy in noticing uses of common memes and cliches, and I like to surprise them.