Your synopsis should contain only what will happen in your book or play or article. Don't editorialize about the significance or the deeper meaning. Also see Query Letter. That sounds rather harmless but vanity publishing often is an expensive way to feed your desire to see your name in print. Remember, a vanity publisher makes no selections among manuscripts and is willing to publish garbage along with the meritorious.
Commercial presses publish garbage also, but they are trying to produce a marketable book.
A vanity publisher has no reason to care since his profit is assured. No commercial presses I know of advertize for manuscripts. Some small press magazines may advertize for submissions to the magazine, especially when they are beginning. A sign of a hidden subsidy vanity press is the one that doesn't ask for money until you have submitted your manuscript. For publishing a book, the cost is much too high in relationship to the product you get.