Link-buttons and button-links

I'd like to hear your opinions whether or not using buttons that look like links (text links, especially when styled the same as links) and links that look like a buttons is a good practice. I feel that making a link look like a button, and vice versa, is materially dishonest and is deceptive. It tells users that links and buttons are the same but they aren't. For example, users might expect to be able to open the buttons that look like links in a new tab or window but that obviously doesn’t happen. Links should be navigational and buttons actionable but then again we have buttons labeled "next" to go to a next step in wizards etc. Can anyone help to understand the convoluted science behind these components?