What the article states is not true (but - at the same time - it's not false!): it's simple, you can buy "truffle oil" that does not contain truffle, or you can keep your eye sharp (and pay more) and buy oil containing real truffle (I have done both!)
Same applies to a lot of food out there. Here is a good example, olive oil: http://www.marksdailyapple.com/is-your-olive-oil-really-oliv...
Of course you can buy perfectly genuine, high quality, olive oil, you just need to know how to pick. The same applies to truffle oil.
The article is really saying that there are brands out there selling artificially flavored truffle oil (not a great surprise, if you ask me), and it fails to clarify a number of underlying premises it's making (or should be making). For example:
1) it is just not true that truffle is the most expensive food in the world. WHITE truffles are. Black truffles are a lot more common and a lot less expensive.
2) white truffle and black truffle are very different: not only they have a different taste, or grow in different geographies, but you eat them differently. For example you always only eat white truffle raw, while you usually cook black truffle. Truffles oil is normally made with black truffle, because the flavor of white truffle is hard to preserve in olive oil.
3) truffles are an underground mushroom. Like all mushrooms, there are many varieties (beyond the fact that they may be white or black), some are more flavorful than others. Their flavor is also affected by the type of tree they grew on (on the roots), which I think it's quite interesting.
4) black truffles grow in a handful of geographies around the world (the best ones are normally considered to be from France, Italy, or Spain), they last several days so they can be transported relatively easily
5) high quality white truffles come only from one - small -region in Italy, they last only 5-7 days from the moment they are picked and are difficult to transport (without making them spoil). The world's capital of white truffles is here (for October to December): https://en.wikipedia.org/wiki/Alba,_Piedmont
People spend huge sums for white truffles, some get bought for $30k, $40k or even $50k, which are even more astounding amounts, if you consider they are for a rock-like looking mushroom that will flavor one or two meals for you and will otherwise spoil in a few days...
Bonus fun trivia: truffles have not been successfully farmed, so they have to picked in the wild. Picking methods are different in different parts of the world: In France they normally use pigs to sniff truffles in the forests. Apparently one of the essences emitted by truffles is similar to sexual feromones in pigs, so they are naturally attracted to them and instinctively dig in the ground for them (but then the truffle picker has to pull The pig away before it the truffle gets eaten). In Italy, they use dogs. It takes years to train a dog to hunt for the smell of truffle (they told me 3-5 years is common), but then dogs do not eat truffles and when they find them, they carefully dig in the ground without breaking the truffle.