Because Jose Sugarman said:
"Copywriting is a mental process the successful execution of which reflects the sum total of all your experiences, your specific knowledge and your ability to mentally process that information and transfer it onto a sheet of paper for the purpose of selling a product or service."
And Gary Bencivenga said:
“The best copywriters are the most tenacious researchers. Like miners, they dig, drill, dynamite, and chip until they have carloads of valuable ore. John Caples advised me once to gather seven times more interesting information than I could possibly use… Research is the infallible cure for writer’s block.”
So over research. It pays. Gives you material to work with. And helps you understand your market even better.