The motivations of the powerful are most likely so perverse as to be incomprehensible to me.
My best hope in this is to point out the threat to their existence. The French aristocracy may have maintained their fortunes and heads if the proletariat were enfranchised.
Pragmatically though, by vastly increasing the available capital and cash flow, those who already hold the wealth will be positioned to better capitalize on the activity, in spite of increased competition, and reduced control, from the enfranchisement.
While much wealth is derived from destruction, stability is far more conducive to increasing wealth and influence. This seems to be the disconnect from rational thought exhibited by those of wealth.
The powerful are no more homogenous a group than others, their individual motivations are wide ranging, and they are in competition with each other. While some would experience setbacks from a world with less conflict, most would simply gain new opportunities. They may even be pitted against each other on this.