Especially this tendency became wide-spread after the success of Flappy Bird. Many beginner developers thought, that if a super-difficult game became popular, that if they'd made a super-difficult game, it will instantly become popular. We've got a flood of really difficult games, but most of them failed to grab the player's attention.
But the point is that even "hardcore" game doesn't mean "punish the player for every mistake".You don't need the player to leave after the first mistake. Let's look at one of the classic games, Canabalt. It gave birth to the whole genre of runners-jumpers. The game is really difficult, but addictive. The treatment of the players' mistakes in interesting there.
The real platforms' sizes in the game engine are a few pixels more than the platforms' visuals. This gives the player an chance to jump right from the edge, even to be tiny bit of second late, but still jump from the very edge of the platform. Thus, the player experiences a "near-miss" emotion, which tightens the link to the game.
Another good example of how forgiveness increases game's playability is Super Sneak Story. In this game you play as a robber who mustn't be spotted by police. In most of the games of this genre "being spotted" = "game over". But not in this one. If the policeman sees you, the new game phase starts: a Chase! You still have a chance to evade the police. Even if the distance between the burglar's and the policeman's sprites is few pixels, you still have a chance to perform an unexpected maneuver and hide.
This advice can be applied to the game of any genre. For example, in any game which has bonuses and enemies, you can make the actual sizes of the bonuses slightly bigger than their visuals, and the enemies - slightly smaller.
Always keep in mind, that the players see your game for the first time in their lives. And they have a great variety of games to play, instead of yours. And your task is to keep their attention.
So, forgive slight player's mistakes.
More game development advice in my thread at FGL
