I've often wondered the same thing about lots of products. Can't prove anything, but, I firmly believe lots of this stuff is just re-badged. Sorry I'm so cynical but life has taught me to be that way.
Some of that is very true. I use to work at a hardware store, and we sold "Store brand" christmas lights, and "GE brand" christmas lights. They were both GE. Same lights from china, same box, just different logos. The back of the 'store brand' even had a GE logo and said "Made by General Electric". It EVEN had the exact same model number on each respective model. But the "store brand" was $1 cheaper (regardless of size or type, they were all $1 cheaper). Some demanded the GE brand, even as I (and even the owner of the store) told them the store brand was the same (he actually made more profit on the cheaper store brand- go figure, but kept the GE on the shelf as some demanded it).
One thing to watch out for though, is sometimes the off brands are A) knock offs, they are built in China using certain standards, the factory rips off the design and uses cheaper materials and less-tight tolerances to sell a knock off. B) stuff that didn't pass the name brands QC. It's not uncommon for a big batch of product to 'fail' quality control (something as simple as an incorrect color on the plastic, to as major as a high failure rate during QC testing), and then have a knock-off brand label slapped on it to sell the already produced product but not tarnish the brands image (Begs the question, is buying a product a person refuses to put their name on wise?). Finally, some of these companies do in fact make two seemingly identical products under different brands, but use cheaper materials and looser tolerances (making them less accurate/reliable/high quality). So it's a trick of figuring out whether you had an identical product that rolled off the line and went into one of two boxes, or you have a cheap knockoff or even something that failed quality control.
It's kind of like some cars. Take the VW Toureg and the Porsche Cayenne. Same platform. They share a LOT of the same parts. However Porsche uses higher quality materials throughout the vehicle, and includes features and amenities not available in the Toureg. Although, technically, at the bare bones they are the same SUV. So while you could say your Toureg is "basically a Porsche", it's not QUITE the same as the workmanship and quality of materials does differ (as does the price tag- by a lot!)
FINE W/ ME 
