Q:

Is it possible to get a "crutch" when learning to draw that will stop you from drawing well?

Recently I have started learning to draw. I watched some proko tutorials to learn the basic idea (that I'm generally supposed to think in 3D, what are bodies made of etc), consulted some books, watched some paintings from the past to see what they did etc. At the moment I still need a lot of practice (of everything, basically) so I still draw like an elementary schooler, but in general I've been having fun and I liked where I was going.
Recently, however, I recall that way in the past I heard some statements by people who uploaded images on the Internet who were greatly dissatisfied in their ability to draw, and where they are as an artist, and blamed that on learning to draw some way which permanently (?) gimped their ability create the art they want. Usually they referred to manga-style, but I've also heard of someone who tried to copy pictures by hand (in an effort to be a hyperrealist artist), realised that despite being able to copy extremely well he does it a "wrong" way he's dissatisfied with (I think he couldn't do anything beyond copying), and had to relearn everything from the start.
Are those real dangers I'm about to get myself into? I don't really recall any skilled and accomplished artist to talk about it, is it because they never encountered any such problem, or is it a made up issue? Is there a way to avoid such a great flaw?

A:

I'm not great and accomplished artist, but I do spend a great deal of my time and passion drawing. Take my thoughts as you will.
No, I do not think there is any legitimate concern about learning to draw a certain way and then being stuck that way throughout your career, so long as you continue to practice. 
What, how, and how often you study and practice are going to have the largest effects on your outcomes. If you only practice exaggerated styles, like manga, anime, or cartooning, then you are very likely to struggle with the anatomy-based styles of Western comic books. Or vice-versa. If you only draw people, then drawing animals won't simply come naturally. You can't just jump from point A to point Z.
There's always something else to learn and practice, or ways to elevate your current skills. The biggest challenge may simply be recognizing what your current weakness is (that you wish to address) and how to actually address it. 
Consider this "short" list of drawing and drawing-related skills, and you'll begin see that there's a wealth of areas to practice and grow in:

Pencil control (straight lines, round circles, light vs heavy)
Line economy
Drawing what you see (vs what you think you see)
Using tone
Light and tone
Shading techniques (each technique is really a separate discipline)
Line weight
Perspective (there's many kinds to learn)
Human anatomy (each part of the body can realistically have its own course of study)
Animal anatomy
Facial expressions
Exaggerating features
Cartooning principles
Defining features of the "genre" you're targeting (anime, comics, cartooning, animation, French animation, etc. etc.)
Plants
Landscapes
Backgrounds
Technical drawings
Thumbnailing and silhouetting 
Vehicles and machinery
Building design
Folds and drapery
Clothing design
Contour drawing
Negative space
Composition and layout
Constructive anatomy
Caricature
Concept design and the iterative process
Sequential art and storytelling

I'll stop there, but be aware that this really is a short list, and each bullet point itself has a number of sub-topics, and the amount of time that can be put into studying each thing has no upper limit. 
While that may seem obvious, I find that the non-artists I'm exposed to are often not aware it. Drawing is often seen as something as people are either "good at" or not, but the fact is that the people that are good at art put in the time, just the same as any other skilled hobby or profession. Your favorite works of art often represent hundreds, but more likely thousands, of hours of dedication to the craft.
Just be careful to not get intimidated by everything that's out there! View it as opportunities, and a well that won't run dry.

