Those are Jewish cities even if they are "illegal" according to some law. 500,000 people, many of whom were born there, are not going anywhere else, even most Arabs understand this very well. If there will be an agreement settlements will be annexed by Israel in exchange for equal land from Israel proper, possibly with Arab population. This has been the formula for every negotiations held so far. So the constant attacks on construction in Jewish cities are motivated by racist hatred, nothing else.
Syrian army troops make gains near Aleppo, retake nearby village (AP)
from the article: MKs urge boycott of Israeli companies building new Palestinian city