There seems to be two different complaints about EE.
1. They show data to Google but hide it from visitors unless they pay. Personally I see nothing wrong with this as explained by edanm. They are a business and this is their business model. They use a search engine as a form of free advertisement. If the search engines didn't have a problem with this then I don't understand why potential visitors should. If you don't like having to pay for the content then go elsewhere. Having results in the search engine that have data behind a paywall is the problem of the search engine, not the site that has the paywall. The data is still relevant even though you can't see it immediately on clicking the link.
2. They show one set of data to search engines but show a different set to visitors. To me, this is a no-no as long as they are actually doing this in the described manner. If by showing different data is because of the paywall and they do match up after you pay, then I see no problem. But in the end if they do not match then there's a problem and I would hope that the search engines would discourage this type of thing.
I think people need to be more clear on what exactly they are complaining about.
Plus, as edanm states, you shouldn't down vote someone simply because the statement is unpopular yet relevant to the topic.