I used to call them "plop quotes" with my undergraduates.
Quotations aren't a rest from the work of analysis and argumentation for the writer. Don't just drop long block quotes into your manuscript and run away, leaving your readers to figure out why they're there and how they relate to your argument.
Quote ONLY the important, memorable, salient phrases, and paraphrase the rest, connecting it to your argument. Show why your reader needs to bother with this material. You digest the quotations for your reader—you're the mama bird regurgitating this information into your readers' frantic, gaping beaks. They'll choke on anything too big. (Truly, most readers—EVEN ME—are inclined to skim block quotations; definitely don't bury crucial points in them.)