Their incorrect prices affect a very high number of viewers: the ones who are checking the price live, and also ones that are checking the historical data they provide.
coinmarketcap.com is a terrible site mainly because of the way they are ranking coins (based on market cap) and have other misleading rankings such as "dominance" but all the data they provide is accurate. whether some people don't understand it is their own fault.
Yesterday was almost 2% difference, tomorrow may be 5%. I don't accuse them to be intentional, but they're providing false information, and that must be fixed. Please raise more awareness.
did you even read any of the replies?!