I will summarize my objections which are generally applicable to the various ideologies and philosophies that emerged from the "Enlightenment."
1. An exaltation of individual reasoning, and the accompanying progressive improvement and emendation of ideas, rejecting tradition and revelation as having any binding authority. Diacritical reasoning is considered man's highest faculty and any spiritual faculties are ignored, dismissed, or given lip-service. The reification of the individual as arbiter of truth.
2. A reductive, narrow approach to the natural world, in varying shades of dualism, empiricism, or materialism. A blanket exaltation of "science" and a degradation of "superstition" including any sense of wonder or mythos. A sometimes mechanistic conception of nature and ultimately of man.
3. The conviction that man, by his own will and reason, can make himself, society, and the world perfect, with the various utopian ideologies that result; the belief that, where individuals are free to exercise public reason, the truth will inevitably emerge.
Really, to identify the basic problems with the Enlightenment, one need look no further than Kant's essay "What is Enlightenment?" His answer: "Enlightenment is man's emergence from his self-imposed tutelage"- such self-imposed tutelage includes any doctrine or tradition which contradicts an individual's personal reasoning and experience. Dogmas are considered fetters to be thrown off in favor of a supposedly free inquiry into the truth.
I think history has well enough demonstrated the limitations and dangers of these ideas- nay, dogmas- which emanate from the enlightenment, but the same old cliches continue to be disseminated through the schools, the media, and the average "freethinking" conformist.