It happens in pretty much every development. As I mentioned before, they build it quick and they build it cheap. They use foreign workers because they don't have to pay them as much. The more units a worker finnishes, the more money he/she makes.
Developers are known for cutting corners with poor quality products. Instead of buying from Canadian or American manufacturers that offer warranties, they would rather purchase poor quality products from China with no warranty.
I have seen a worker that forgot to plug in a dishwasher properly, which caused multiple units to be flooded. Poor quality copper in the plumbing will cause major leak issues - I have spoken to plumbers who say they have never seen 3 year old buildings with so many plumbing issues. I have spoke to Locksmiths that are making a killing off certain buildings because the developer decided to use poor quality door handles/locking mechanisms. The list goes on and on.
Sad thing is, everyone's hands are dirty - there is no protection for buyers regardless of what is said.