The thing is, SRB2 isn't slippery and hard to control. Look at any experienced player playing the game and it's quite obvious the controls are great. The actual problem is that the controls are not intuitive.It's has to be open minded and listen to feedback from everyone if it were to appeal to bigger audience, offer SRB2 to any outsider and he will quickly notice how slippery the controls are and how hard to control the game is.
Players new to SRB2 will look at the game and (reasonably) expect that the game controls and acts like modern Sonic. It doesn't. Not only does it not act like modern Sonic's controls, we do allow the player to make it badly fake modern Sonic's controls with analog, and when they do they find it hysterically slippery because while analog initially appears to emulate modern Sonic's controls but it doesn't at all.
This is the reason for introducing auto-brake, directionchar, and accepting that we need to create a tutorial. It's not that our game controls badly; it's that we do a terrible job of explaining to players how to play our game. They then assume that it controls a way that it doesn't, and then they have a terrible experience playing because of that.