While jews and many other groups (especially whites considering themselves christians) tend to use the holocaust as an "excuse" (when they lack actual arguments) for Israel to exist, that doesn't apply to all jews nor does it mean that there is no point to it.

Further, the "alleged" Holocaust can be thought of in many different ways. Even if much of what has been said previously would be proven untrue/could not be proven true, this doesn't change the fact that jews were one of the groups viciously dehumanized and killed off.