I find it a bit disingenuous that this is not being disclosed, considering that there are numerous Ethereum competitors (primary, Bitcoin with SegWit, coming 2016, and Storj, Maidsafe).
I thought about adding the disclaimer and chose against it. Maybe I chose wrong. I sort of see your point about conflict of interest, but that line of thinking also disqualifies almost all of the people who are most intimately familiar with the technology.
If you're skeptical, lets have a conversation about it. I regularly describe my position as skeptically optimistic about Ethereum's future success.
Yes, when one is advocating for and recommending a product, it is pretty standard (and, in my opinion, an ethical requirement) for one to also disclose that he/she is heavily involved with that product. It is even more important when one stands to benefit -- especially financially! -- from the product's success.
One's credibility quickly goes right out the window when one fails to disclose these basic facts.
Last year, I was driving across the country and needed a place to crash. I randomly looked for someone from a PyCon list and found Piper. He was happy to let myself and a friend sleep at his home; he introduced us to his family and greeted us warmly.
So, take his words with whichever grains of salt you find most relevant.
Furthermore, I find your comment extremely suspect, considering you also have a top-level comment [1] in this thread that basically amounts to "guys, guys... there's no reason to worry about this bill!"
If anyone's motives should be questioned, it's you.