Not really getting their graph. They seem to be saying that more transactions = decline in price because these transactions go to merchants who cash out for fiat. But not all things are this flat out.
Some merchants do not trade BTC to fiat, or they hold a % of BTC and cash out the rest. Also, most of these transactions aren't even probably going for merchants, or are aiding in product exchanges...
The thesis of the article seems to be that this BIT trust would drive or allow more competition by longer term investors for these scarce resources (btc) to offset the former point of merchants cashing out, thus turning the tables on the selling pressure.