If they do not come with a will or mission to work, even the 3 months probation cannot help much as their performance will deteriorate after then.
What can help may be for the government to suspend visa application for those who do not finish contract for 6 months or more - to increase their cost of non performing. This can stand as a threatening factor for good performance.
The prevailing law and regulations are set up decades before for sake of protecting the weak. But the world change, they are not the minority nor the weak. The employers to certain extent are the weak in this aspect. Besides, as a government, the rules and measures should be set up for protecting its citizens. However, if this really happens, there would be noises from the barristers, long hair (dont know when they come under the same category). Mentality of the government is to minimize being criticize. So, we all will end up with long neck...
Many maids are not good nowadays.... It seems they don't mind and easily suggested employers to terminate them. Many like to look after old people instead of babies. It's really hard to hire a good maid now....