Mario games = Good. You almost always begin in a safe environment that let's you do whatever the hell you want and play with all the buttons, you have most moves available from the get go, and there will also be a SHORT, AND OPTIONAL helper dude or dudette there to helpfully say 'shake the wii-remote to activate the thing!' or 'Tap A when you land to jump higher!' It's non-intrusive, helpful, and awesome. It lets you figure things out for yourself, and if you can't, the explanation is quick and direct. New comers and veterans feel welcome.
Final Fantasy XIII = Bad. You can't play the full game until 25 hours in and it's all tutorials up to that point. You can't experiment with new leaders or characters up till that point, and most of the game is tutorials on how to fight...WHILE you fight. That's a major issue. It's always better to just make the gameplay somewhat 'obvious' and intuitive, then when things get more complex, make a hands on tutorial or an optional text dump or guide. That's what almost every other Final Fantasy did, as a matter of fact. FFXIII is simply patronizing and it burdens the player with massive dumps of info at once.
Like people have said, it's a matter of preference, so you need to accommodate for everyone. It's harder to program and takes some time, but it's an important part of good game design.