I agree that immigration was possibly a factor, however I would think that it wasn't immigration itself that upset people but the fact that the EU controlled the immigration and even promoted it against our country's wishes.

I see most of the concerns about the EU from the UK perspective can be narrowed down to control, ie sovereignty.

Germany has gone further past the tipping point of becoming a Muslim country than we have and perhaps had surrendered to the idea, perhaps we think that we can prevent that happening in the UK although the stats at the moment show that we will be unlikely to succeed.

Note that yet again, Germany has much more influence than the rest of the EU put together, in this case on policies of immigration. How can this be unless it is the United States of Germany? Just go through a list of the EU countries noting who would be for and who would be against mass immigration, Germany would be well out-voted! Only since Brexit has Germany been forced to climb down a few steps.