On one hand, it is easy to understand why Israel is doing what it's doing. Beyond that, it keeps Israel's vital arms industry humming. Beyond that, it's good to have China as a friend, especially as it grows in influence. Beyond that, it gives Israel entree to a huge new market. Bottom line is that the sale is very good for business.
Problem is that it's very bad for the soul of Israel.
That is the whole reason for there being an Israel. And so, Israel shouldn't be just be another country in the arms business, one that cares more about sales than friends. And Israel shouldn't just ignore the threat these systems pose to Taiwan, a country, like Israel itself, surrounded by hostile neighbors, a haven of democracy in a sea of dictatorships. Israel, of all countries, should stand with Taiwan simply because it is the right thing to do, even if it brings it no hard currency or political advantage. But most of all, Israel should recognize the impropriety of supplying sophisticated military hardware to a country that does not allow its own citizens human rights and freedoms and jails those who oppose the government.