please, no one was beaten in a german airport.
The reason Europe is *sometimes* harsher than the US (they still haven't gravitated toward being the opposite of "so lenient"), is because they have already suffered at the hand of illegal immigration.
You see, most European countries have a very socialist structure, with the government providing such services as health and amenities such as monetary awards for having children (you can say the IRS is evil towards families compared with places such as Scandinavia (that's a region) and most others).
Right now, if you walk in Paris you'll see more foreigners (particularly muslims) than Frenchmen. If you've been following the news, Paris has suffered many riots, often by muslims (not an extremist writing here). The same goes for Germany and Britain, somewhat Spain and Italy. Europe has over 60 million immigrants from the past decade, with over 50% coming from North Africa/Middle East.
You can get a sense of why Europe is starting to have had it with the immigrants.
On the other hand, in America, what's not to like? We treat our Mexican neighbors well, wouldn't you say? Who's the construction worker? Who mows the lawn? Who wipes the hotel floor? For us Americans, the Mexicans are doing all the gritty work, so even though they're illegal - we take advantage of that and pay them in pennies.
How's that for an answer?