There are some differences betwee summarizing and quoting. Summarizing: doesn't match the source word for word, presents a broad overview, so is usually much shorter than the original text, involves putting the main idea/ideas into your own words, but including only the main point, must be attributed to the original source. Quoting: match the source word for word, must be attributed to the original source, appear between quotation marks, are usually a brief segment of the text. So, as for me, summarizing is not really useful alternative to quoting.