It's luck because no two kicks are identical? By that logic every single sporting action is luck because it's never the same. Hockey goal. Golf shot. Tennis serve. Football pass. Etc.
If you think there is no luck involved in those, you are kidding yourself.
What causes "luck" in sporting events? Mostly uncontrollable factors. If you take a machine designed to shoot/hit the same object in the same way multiple time, you are going to get a gaussian distribution in its final position.
The difference between a skilled player and one that is not is that the skilled player will have a narrower gaussian - ie the variance in the final position will be smaller.
Let's go back to soccer. Uncontrollable factors include those I mentioned.
Let me just concentrate on feet angle+point of contact on a penalty kick. At such speed/velocities as a player kicking a ball on a penalty kick, it is almost impossible to control with GREAT precision the place where your feet will hit the ball, and the angle/shape your feet will have. Just taking a very simplified model which assume a player is so skilled he can control with 2° precision the angle of its feet in both orientation (aka ±2° - and I guess it's probably a greater precision than what any soccer player can achieve), and assume this is the angle at which the ball will depart, and assume absolute vacuum and perfectly spherical ball that does not deform, this simple ±2° causes a ±0.4m variation in horizontal position of the ball (only horizontal - i haven't done the analysis for vertical position). It is a noticeable difference, and other factors were not taken into account. There are other factors that will slightly reduce that variance, while there are factors that will increase it, while some will just not matter much to be noticeable in a real world context.
In the end, I'm not saying skill does not matter. It matters in REDUCING the impact of luck/randomness. But, since we live in a real world, it is impossible to completely eliminate the impact of luck.