It drags site quality down to the ground. Rephrase requests are extremely easy to ask - all you need is a sentence! - but also pretty uninteresting to anybody not attempting to write that particular sentence. This results in a large number of poor, uninteresting, and unhelpful questions - making the site, as a whole, suffer. The worst effect is that a flood of low-quality questions drives away experienced contributing users, who feel that the site is dominated by content which has no value to them. (See, e.g., the recent closing of Literature.SE: Why did Literature fail?Why did Literature fail?)
replaced http://meta.stackexchange.com/ with https://meta.stackexchange.com/