I wasn't going to post an answer because there are several answers here that address what I wanted to address, the downsides of this approach and the possibility that perhaps you also need convincing to do things a different way, not just your parents. However, they don't mention some important things I think should be mentioned.
My story is very similar to your own. I was bored to death in school, I missed more school than I attended (in high school years) and still managed to keep passing. I was bored even in programming and tech classes, so bored I opted to hack around and do stupid things like give all student computers on the network full administrator rights, etc. I thought I was very smart and yes actually in my environment, I was exceptionally smart.
Before downvotes come in for calling myself exceptionally smart, look again at what I said. In my environment I was exceptionally smart, the same way that a mathematician hanging out with non-mathematicians is exceptionally smart. You'reBut you're not in the adult workforce with other professional programmers.
If You Choose Not To Go To College
You have not held a job where you need to perform along sidealongside people who are most likely "smarter" (better)better than you at your common craft and are constantly measuring you against their own performance, expecting you to keep pace. As you already know, programming is something that is constantly evolving, you must always be a student of this craft, which leads to an important consideration no one else has mentioned so far.
I'm not meaning to speak down to you when I say this, but thingsThings change drastically when you become a fully independent adult. Things happen that are beyond your control constantly and you must adapt to them. As others have mentioned and I can confirm, you can do this the way you propose, but you must invest a lot more time and effort on your own time. You need to be exceptional to prove that you can perform in your chosen career without a piece of paper that says you can.
Have you considered how difficult it would be to do the extra studying and publishing open source code and blog writing etc while being in a relationship? What about if/when you have children? "I would focus on building my career before starting down that road." - Okay granted, but what about when your chosen career that you've focused all your energy on proving you can do without a paper dies?
Happened to me, I proved myself as a flash developer and we all know what happened to flash, I was back at square one with a wife and two children with absolutely no published work or work history to prove I can do anything else. Even loving my craft and excelling at it, do you know how difficult it is to read Andre Alexandresu's Advanced C++ between dropping off and picking up kids, running the errands needed just to keep the house going, trying not to stroke out while opening my hydro bill that increased 30%, reading my credit card statements and oh yeah, doing my existing job? It's not hard, it's prohibitively difficult.
Your parents know these things. They know how adult life unfolds in an unpredictable way, how you're spending more time reacting than calmly watching plans unfold exactly as expected. They are trying to help you, but I think you do have a valid point though about how they're trying to help you.
It sounds to me like this whole situation can be resolved by having clearer, more open dialog with your parents.It sounds to me like this whole situation can be resolved by having clearer, more open dialog with your parents. Both sides need to be open to being wrong and having their plans scrutinized by each other. You need to explain to your parents that you've dug your heels in and decided to go against their direction for your life. It might not be pretty, but it sounds to me like this is because they've already dug their heels in too.
However, if you were to present them with news of a coming doomsday to their plans for you, but also leave the door open for some hope of a compromise, they may become flexible to opening dialogue to try to salvage at least some of their planshopes. Don't be harsh, but communicate your position firmly.
Remember that no matter how strict they are, they are your parents and love you immensely. It's from this love that these plans come, no matter how flawed they are. Communicate this to them as well, as I'm sure you love them. I have yet to encounter a conflict where a clear expression of love from my children can't soften my heart in even the worst of moods. As someone else mentioned in a great answer, a letter may be the most effective method to break the ice on this issue. Wish you all the best.