I think, broadly, there are two main reasons the UK will never stop the small boat issue. Firstly, the government don't want to stop it as it helps deflect from their other feck ups. Secondly, we live in a democracy with a multitude of laws to protect peoples rights. I'm not saying this is wrong, I'm not saying this should be changed, I'm simply asserting it's another reason the issue drags on and on. e.g. as soon as possible resolutions are suggested, various groups and legal bods jump all over them and they go nowhere.
Let me give an OT example. I imagine in some/many countries if you're a landlord and your tenant stops paying their rent, you can have them out within weeks if not days. Here in Scotland thanks to increasing legislation to protect tenants, I had tenants that paid rent 1 month out of 11. They eventually left of their own fruition which was a good job, as it might have been possible for them to remain in the property for another 6 months before I'd have a chance to evict them. So theoretically they could have lived in the property for up to 17 months having paid rent for 1 month. And all the while protected by the law.
My point is, regardless of whether you agree/disagree with folk coming in on small boats, it's our legislative and legal system as much as anything that creates a barrier to stopping it. That and the incompetence of government.