Sometimes you just need a quick gig to make ends meet between jobs. Something you can pick up in a day or two and leave just as quickly.
Full-time, long-term? No, it's not a great idea. But it's a good safety net when things get tough.
A lot of Americans point to Canada as an example, but it's a pretty bad example. If healthcare was so great in Canada, then there wouldn't be private hospitals in the United States that cater only to Canadians who go to America for the healthcare they can't get in Canada, or can't get in a timely fashion.
In American towns where a lot of Canadians spend the winter, the radio stations are full of ads for these hospitals. (Palm Springs, for example.)
If you mean the UK, the news over there is constantly full of horror stories about its NHS.
Perhaps you can be more specific?