I think another common misconception about people who commit suicide is that they must truly hate themselves in order to go through with it. Perhaps with some this may be true. But with many, what they truly hate is the major depression they must live with every day. In this sense, I think it may be compared to a form of terminal cancer.
To someone living with depression, their condition might seem as an incurable progressive and debilitating disease that causes unbearable suffering. Rather than see it through to the bitter end, some may opt for a form of euthanasia. In this sense, it is no more self-hatred than a dying cancer patient who takes an overdose of morphine to speed himself on his way.
When you hate someone, it is common for you to wish them to suffer. The purpose of euthanasia is to end suffering. It may be seen by some as a form of loving kindness. For someone who kills himself to end his own suffering, it may be an expression, albeit misguided, of self-love.