As long as the welfare state / benefit system still exist you will find people still willing to risk it all to try their luck.
My parents used to ask me why I was earning peanuts while others (some of them illegal and some legal short term work contract) that have gone/sent home boasted about the "roads here being paved with gold" and free for all ... some even boasted about being given free home and free maids when one has fallen ill/sick.
To top it up the gov't would give them money too!!! For some they boasted about 5 figures income (exchange rate) per month which sounded too good to be true but then you have to remember majority of those that spoke to my parents were rather illiterate so in a way they would not know what's legal or illegal. They don't care as the chance is too good to miss.
Personally, if I could turn back the clock I would rather be somewhere else than in UK.
Bloody education and loose women brought me here long time ago as a young man ... arrrghhh ... stuck now as I find it hard to learn another language or culture otherwise I would go. Not young anymore. Going home is not a good option now as life will be very hard for a non-muslamic person.
Oh yes ... I am a legal alien but life is still very hard after all these years.