Demonstrating Europe has a large number of anti-Zionists and Europe has a large number of anti-Semitic attacks does not prove causality.
Anti-Zionism does not create an environment for anti-Semitic attacks to take place. The two are entirely independent and unlinked.
Firstly, there are many anti-Semites who actually embrace Zionism. In 1905, the former British foreign secretary Arthur Balfour supported the Aliens Act, which restricted Jewish immigration to the UK and was widely seen as an anti-Semitic bill. In 1917, he also asserted he was very much in favour of Zionism.
The fact that the two beliefs can be held concurrently disproves any notion that anti-Zionism creates fertile ground for anti-Semitism. Anti-Semites come from all sides of the Zionism debate. Many argue for it and many against.
Secondly, the vast majority of the anti-Semitic attacks which are carried out in Europe are carried out by radicalised Muslims. It would be a far more accurate statement to assert that radical Islam creates an environment in which anti-Semitism prospers, not anti-Zionism.