As always, test. I'm broadly supportive of this advice, but I know people who do long-form copy and see conversion rates slip when they switch to short form, and (while it isn't long-form) the BCC home page historically performs better with lots of text than with little.
Yes, one example of those kinds of pages are the never ending sales pitch pages (e.g. selling parrot training). So, text _per se_ is not a bad thing on a page. But you have to provide proper flow and layout to generate interest and then seduce visitor to that prominent 'Add to Cart' button.
