In programming things will be a little different.
First, as mentioned, a lot of content can be developed based on Open Source code. Some of this code requires credits to be given, others do not.
If the code you use, edit and publish doesn't require to credit the original author, that's fine when it comes to copyright laws. But if you pretend you wrote all of it, it's still plagiarism.
That is true.
But for a programmer to say that was simply ruining his career, because saying that he did something that in reality he is not capable of doing, is not very positive. It's better to say that you used a certain tool and receive credit for knowing how to use it very well, than in the end losing all credibility.