To solve this problem, the NFL (National Forensic League) created a new form of debate, called Public Forum, that focuses on clear, persuasive rhetoric at the expense of detailed research. And now it is starting to mutate just like Lincoln-Douglas.
I think that fast-talking and reliance on out-of-context quotes is sort of the dominant strategy for any kind of debate. As long as there is a rule than an unrefuted argument stands as true, quantity will inevitably become more important than quality, and the credentials of a source will be more important than what it actually says.
This process doesn't occur when judges are allowed to make their decision based on persuasive speech and rhetoric as much as on logic, but debate judging is already so subjective that this presents a problem for many people.
I never liked the alternate forms of debate that attempt to re-create some golden era of slow talking persuasion because the decisions made are often arbitrary. I prefer a value-neutral environment where I can be assured a more objective basis for judgement.