Remember that philosophers, like everyone else, lived before the idea of motivated cognition was fully developed; it was commonplace to have theories of epistemology which didn't lead you to be suspicious enough of your own conclusions. You may be holding them to too high a standard by pointing to some of their conclusions, when some of their intermediate ideas and methods are still of interest and value today.

However, you should be selective of who you read. Unless you're an academic philosopher, for instance, reading a modern synopsis of Kantian thought is vastly preferable to trying to read Kant yourself. For similar reasons, I've steered clear of Hegel's original texts.

Unfortunately for the present purpose, I myself went the long way (I went to a college with a strong Great Books core in several subjects), so I don't have a good digest to recommend. Anyone else have one?