Yes, on a desktop or laptop computer. Not so easy on a phone/tablet.

I don't think it's bad in the least, not unless it's overused or used improperly. If a "login" link opens a new window, that's obviously poor use. If it's a link along the lines of "view this supporting article that's on another site, then come back here and join the discussion", clearly you want a new window opened - both the author and the reader want that done. Does the target site hijack the "back" button in the browser? Who cares - I've opened a new window/tab and, when I'm done, I'll close it and return to the article I was reading.