http://www.significant-bits.com/super-mario-bros-3-level-design-lessons
I know there’s a similar article like this for SMB1 out there somewhere; just can’t find it right now. But it does explain the intuitive teaching style of SMB1 and SMB3, which really just isn’t present in SMB2.

You are right that most games didn’t have tutorials then, although many did. But what they always had were levels designed to teach you gameplay one piece at a time. 

The original Mario totally teaches you how to play, in fact I think it has one of the smoothest integrations of learning ever. Each new element is introduced one at a time, very carefully. First you learn how to run for a few seconds, then you’re given a goomba or two to bash, then an item box, etc.

SMB2 doesn’t do that, it just drops you in, which would be less of a big deal if it wasn’t a sequel that shared almost none of its ancestor’s basic mechanics. 

Lemme be clear: SMB2 is a great game, most of the games on this list are great, and of course you figure it out eventually, but a little hand would have helped. 

Basing this off of the major differences between Mario 1 and Mario 2 doesn’t make any sense. Where in the original Mario Bros. did they ever show you how to play? Nothing was ever explained in these games.

Nowadays, most games tell you too much.