I see this common mistake throughout DFW on projects that deserve better. Personally, I believe either the landscape contractor doesn't know any better or just doesn't care about their quality of installation. Hopefully this post will reach some of them and they can improve their installation quality with a simple solution.
Why is this installation a mistake in my humble opinion you may ask? This particular MR16 has only 1"-2" of the provided stake pushed into hard compact soil as seen above. The landscape contractor will then bring in a mixture of 2"-4" of bed prep (soil and mulch) to complete their installation. Over a short amount of time, the fixture will no longer be vertical but will have the customary look of many I see...falling over a bit to the right or left. Whether the maintenance crew, a squirrel, or soccer ball gently touches this light, IT WILL MOVE!
The solution? Make your own stake out of a 12" plumbing pipe and a coupling. Drill a hole for the wire to exit and pound it into the ground. Your light fixture will be illuminating the plant specimen it was meant to for years to come.