Why do I say that it's an excuse? Well, the most successful artists do not go around saying that they do not have the time. Those who are serious about learning how to draw find and make time for drawing. When you really think about it, it does not really take all that long, depending on what you're trying to achieve.
If you can get yourself to pick up a pen or pencil to draw on any piece of paper that you can get hold of for just 15 minutes a day, I guarantee you that your skills will surpass all your peers in no time. If you just improve by 1% a day, in a single year, you would've improved by a whopping 365%!
Try doing that for at least 6 months. Once you get good at it, you'll learn to love drawing even more and it'll become second nature to you. I know because that's what happened to me.
I find it really hard to break out of this habit. Whenever I have some free time, I find myself reaching out for the nearest pen or pencil and started drawing. That's how I improve over the years.
Recently, I launched one of the most complete home study course for learning how to draw and paint on the Internet. Initially, I just have these two huge volumes full of valuable information, accompanied by two textbooks.
But still, people come up to me and say that they do not have the time to really sit down to enjoy the reading. I can understand that. Imagine having to spend time at work, commuting to and from work, playing with the kids, going to the gym and do a hundred different things in 24 hours.
However, remember that successful artists do not find excuses. They find workaround solutions so that they can achieve their goals, which is to learn how to draw.
So I recorded the entire course in MP3 format for these group of people. Now they can listen to the recordings even when they're not in front of the computer.
My point is, if you seriously want to improve your drawing skills, then invest some time and effort into your learning journey. Do not make up excuses. Listen to some audio files if you have to!