There is no doubt to me that immigration is a great thing, but it needs to be in the interests of a country, not solely left to the interests of anyone wanting to do so and then left for that country to have to deal with the consequences of the possibility of too many numbers. That's just asking for a mess.
The theory by the EU is that it can have a successful open door policy.
Well it doesn't take much thought to figure out that this theory will never work.
Lets test it out in more simple terms...
Lets say you were going to organise a birthday party at your local hall and of course you want to make sure everything is well organised to ensure the party is a success for everyone.
The hall can fit 250 people. (think of that as a country)
You order enough food & drink for 250 people, Get 250 chairs, plates etc. & Disco Dave
(that's your infrastructure and services sorted).
How would you invite the guests to ensure the party goes well?
I expect you would probably send out 250 invites or less.
Or you could do it the EU way & have an open door.....
Stick an advert in a newspaper to advertise your party to a few thousand people & say everyone welcome.
What could possibly go wrong?