Well, I don't agree that the short hours work is a result of laziness, its partly because benefits are structured to encourage it, and because employers are trying to use shorter hours as much as possible.
There are two ways of looking at the 'chronic lazy' aspect though. One is that people are most 'lazy' when they find that work doesn't pay, and doesn't give you more and better leisure time - so if I work 40 hours a week and end up with effectively 'the minimum the government says its possible to live on' but with no extra leisure time, and no freedom to find higher paid work, or develop or pursue career development or education, the logical and sensible choice is to stop working - our employers shouldn't be offering so many jobs at a level where not working and starving is a better option than working full time FFS.
The second way of looking at it is that you accept that some people are chronically lazy, or ill, or otherwise completely ineffective/disorganised or unwilling to be productive. If you do accept this, current conservative policy is to force employers to accommodate those people into the main workforce, however damaging they are - by taking away food clothes and shelter from those people, so you either have reduced workplace productivity (as we have now) or you have genuine starvation and homelessness (as we have now). These both have massive social and economic cost - homelessness particularly, court cases, health burden, damage to town centre image and safety, drug abuse, hygiene issues etc.
The added benefit of a reasonable benefit economy is that someone in my position - highly educated, highly motivated, highly dedicated, but who is regularly overlooked and disadvantaged in the employment market, can better route their career, and develop themselves, or even add their skills to voluntary causes, or things they are just good at and passionate about rather than spend 24 hours a day thinking about whether you'll be able to eat at the end of the week.
On top of that last is what happens to the UK culturally when benefits will actually keep you alive - trainspotting, harry potter franchise, films, most of our national comedians, britpop, madchester etc etc all came out of a reasonable life-supporting benefits system where creative people can take an income hit whilst they find their feet.
Also you can't make economic decisions when you are literally scared of whether you will eat- you don't choose, you become max-dependent, so when you do get money, its much harder to manage successfully. - no pocket money won't make an investment banker, tiny bits and choices made as a result might.