It's pretty simple to understand - when a user opens a tool, it's because they want to do the thing that tool does, now. If someone opens my videoconferencing product 98% of the time it's they've got a scheduled call to join within the next 20 seconds . They're not going to be late for their meeting so they can read my release notes. If someone opens my PDF viewer, 99.9% chance they want to view the PDF they just ope…
Interestingly, there are basically two kinds of programs I am sometimes happy to see guided tours embedded in: * Creation programs (image/video editors, 3D rendering... hell, even a slides program or an IDE). Doesn't mean I won't dismiss them sometimes anyways, but these are tools that often I do want to get an initial idea how to use, that I have allotted some time to play around with, and that are sufficiently comp…
Oftentimes it's less jarring to have an invisible tutorial though (a level made to exploit the new gameplay element / feature). But it depends on what you want the user to learn and the type of videogame; I don't mind a guided tour in more strategic games (RTS, turn by turn RPG, ...).