If you search for "Sippenhaft", you'll find that this point of view has been discussed before. While I strongly dislike the style of SVP/UDC ad campaigns and mostly disagree with their positions, an eviction is by the law not a penalty but a measure to ensure public safety (and therefor should only taken against dangerous criminals and not for every crime on the initiative's catalogue). If you ask the other way: Should a criminal be allowed to stay because he's parent of a minor? Didn't the minor just enter Switzerland because of his parents' effort, too? And sometimes the situation might be solved by giving the child custody to somebody else if the criminal parents are uncapable to take care of their offspring anyway.

That said I'll vote against the initiative. The initiative wouldn't significantly change the current situation. A yes for the initiative would give the SVP/UDC too much media attention at home and Switzerland a bad image abroad.