First you have to define what laziness is! I think there is a fine line between "working to living" and well, not wanting to work at all. It's a very, very fine line
My opinion - as always, FWIW - is that the attitude towards work is a combination of several factors:
1) In the lower-paying jobs, turnover (in any country) is always going to be higher. If you combine that with an economic system that makes it very, very hard to get ahead - where is the incentive to work hard? Let's take a cleaning woman for example here vs the US. In two equal cases, a cleaning woman in the US is going to have a much higher income and there are systems in place for example where eventually, she might be able to open up her own cleaning company some day. Here - not so much. So our hypothetical cleaning woman works all day, if she is lucky and makes very little money & all she has to look forward to is a lifetime of that - not so motivating
2) There is not the cultural importance/value/prestige attached to working hard here that there is in other countries. Other things are more important - ex, spending time with your friends and your family.
3) A history of socio-economic upheaval has had some long-term effects on the psyche here. From an extrañjera's perspective - it seems there is very little importance/focus on thinking long-term b/c who knows what will happen anyway? You might as well enjoy today b/c tomorrow it (whatever it is) could all be taken away.
4) A splash of "time is an amorphous"- tomorrow can be tomorrow or next week.
5) And some genuine "entitlement" from workers. It's been an interesting experience for me here as an employer. For example, I offered my employees pre-paid insurance (at my cost). First, there was an uproar that I didn't offer it to their family. Then, once I agreed, there was some push-back on why (again, all at my cost), I wouldn't offer it to girlfriends/boyfriends, etc. Or complaints about why they had to work longer hours (hours that were discussed prior to hiring). Or requests for parking subsidiaries (even though we provided free transport to the office) b/c the transport wasn't convenient to them. It's seems as though it's a very "I want" work culture.
A bit of a perfect recipe for what we perceive as laziness really but I think that's a very limited description...