Sites like My Heritage and Ancestry are interested in making a profit, so they don't provide information indicating that some of their sources, like WikiTree and Find A Grave, can be accessed for free. I wrote to Ancestry once and asked about their policy on informing people about this. Their response was that they are providing a service (for a fee) that allows a user to search a huge number of sources at once, including free sources, and their customers are paying for this added convenience.