Deliberate practice is a very important. When learning a skill, breaking down ideas into small pieces and mastering those segments can lead to competency and expertise if the process is repeated properly over a long enough period of time.
Many people will put in the hours but will not actively engage in practice. This phenomena is everywhere, but it is most easily found in video games. One account of players actively not learning can be found in a blog about StarCraft 2 on TeamLiquid. In this account, the author (a player who was ranked among the top 85% percentile of all players) plays a strategy that has a counter so simple an absolutely new player could easily be coached to beat it via simple instructions. Most people he starts out playing it against do beat him, so he soon ends up playing in a league with the bottom 35% of players. Soon he starts winning about 50% of his matches with a strategy that is very simple to beat.
The mindset of the players who have been playing for a long time and are still really bad at an activity is interesting. Some of them have played for many years, and perhaps if you include their original StarCraft experience they might soon be candidates for the 10,000 hours needed to develop true expertise. And yet this is a group of people who have put in tons of time but have remained generally incompetent. It doesn't make them stupid, but they are definitely suffering from some forms of cognitive bias. Besides the relative immaturity of the players involved (both the author and his opponents), a few things stand out:
1. The losing player blames the game, claiming imbalance where none exists.
2. They declare that the player was not playing fairly. In Starcraft, "cheese" is what other games call cheap. In both cases, the player tries to add extra rules to the game that their opponent isn't necessarily going to follow. This is a little reminiscent of investors creating structured products and claiming that they never expected housing markets to be correlated on a national level during the 2008 financial crisis.
3. They don't look up how to beat the specific strategy and apply the technique. Even more surprising is that some of the players who lost to the author had actually read his blog in which he describes quite clearly how to defeat the strategy.
4. Perhaps the most important factor is that most of the players who have been stuck at their level for a long don't conceive their actions in clear and defined plans. They act on feelings and find it hard to explain why they did what they did when thinking about the game they just played.
The importance of a plan is learned in many ways, but I was first exposed to it through chess. Middle game rule #1 of the Thirty Rules of Chess* is probably the most broadly applicable rules of the thirty rules.
M1. Have all your moves fit into definite plans.
Rules of Planning:
a) A plan must be suggested by some feature in the position.
b) A plan must be based on sound strategic principles.
c) A plan must be flexible,
d) Concrete and,
Evaluating a Position:
b) Pawn structure
c) Piece mobility
d) King safety
e) Enemy threats
Without a clear reason behind actions, in a chess game, a video game or in any activity requiring strategy, there is little room for significant improvement. Playing without a plan or a way to determine whether you are doing well or not is just as bad.
So if you want to avoid 10,000 hours of non-deliberate practice, making sure that actions are formulated around plans with ways to determine whether or not the plan worked is a necessary start.
*Reuben Fine's 30 rules of chess aren't really rules - they are more like suggestions that should be followed about 80% of the time by the average club level player.