All of the AI's in the area work their employees on 3 month contracts. 6 months, if the employee has been with the hotel for awhile. This allows them to send the employees on "vacation" when the low season hits, with a promise to rehire them in 15 days. I know this, for fact, because it directly relates to our business.
We have our staff sign yearly contracts, and it is hard to fire someone, even for cause. When you do, you normally have to work out a settlement, and pay a finiquito, where the ex employee signs a paper stating that they are satisfied and will not pursue it further. You then go to an arbitrator to notarize the document. If the employee fights, they usually win. In order to fire someone, for cause, you have to document the infraction and take it to city hall. This is called an "acta". After 3 "actas", you can let them go, but you still have to pay them. If a employee does not show up for three working days, without notice, you can let them go. Of course, they can claim that they talked to the sectrary's nephew about being out. Unless you have a system in place, that is followed to the T (and you can prove it), you won't win this battle, either.
The law overprotects employees. No doubt. Take the word of people who employ people, in Mexico. They know. On the good side, most of the Mexicans I have had working for me are hard working and honest. I have actually had more problems with foreigners who learn about the laws and try to use them to their advantage. They usually end up on the losing end, because I head over to Immigration and baja them. Once that happens, their FM3 is worthless. I am a son of a bitch when you screw with my livelihood.
Not many sunsets or toes in the water when you work 11 or 12 hours a day, unfortunately.