It's like a lifetime prison! Even if the thief is caught stealing, it doesn't give him a lifetime imprisonment, instead he's freed after 2, 3 or 5 years.
This is not a very good comparison. Don't think of it as a prison sentence, think of it as getting fired from a job. If you get caught stealing from your employer or violating their conflict of interest rules you will get fired from that job, and it's very unlikely that you'll be hired back by that company.
Anyone who is caught plagiarizing on this forum is welcome to seek out membership at a number of other cryptocurrency related forums, and if they're smart they won't make the same mistake there.
I personally have a little tolerance for plagiarism. It's theft, plain and simple.