That article is a bit muddled which, ironically, kinda proves its point

I think URL inclusion, in the form of a flat fee for inclusion of a single page for a year, is very different to SE sanctioned XML Trusted Feeds, and the two need to be seperated in context. Beyond the guarantee that a URL will be in a specific SE index, URL inclusion offers no possible ranking benefit over natural search. Trusted feed, on the other hand, offers the ability to manipulate the data you feed the Search Engines, which is surely very different from a mere guarantee to crawl.
Looking past that, the question is really
what defines advertising? If I pay to ensure a page is in the index, is that advertising? Search engines blur the lines of what is traditionally defined as advertising and what isn't, and there is no off-line analogy that is comparable. Is a free listing an ad? If the search is for "mortgage", what else could it be but an ad? Or is it commentary, in the same way a game review is not an ad? The question then becomes is URL inclusion more like a game review, in which a user has no control over the outcome, or more like a full page game
ad in a newspaper? Personally, I believe it is the former for single URL inclusion, and neither for trusted feed.
If people want to label PI, and more specifically Trusted Feed, as advertising, then surely Trusted feed
should gain some ranking benefit. Otherwise, you are paying
per click for the privilege of what exactly? Being ranked exactly as you would have otherwise? For mine, that is extremely unfair. You get branded an ad, which does have at least some negative conotations, but get no benefit beyond complete indexing of all your pages.
As opposed to Paid Placement, such as AdWords or Overture, on which you can know where you will appear and for what phrases, Trusted Feed makes absolutely no ranking guarantee. Being labelled an ad on top of this is a little unfair.
Also, I think supreme caution needs to be exercised before labelling such listings as ads. Surely labelling these pages as advertising may have the effect of encouraging SE to give such listings a boost. After all, if they are clearly labelled as ads, then why do they need to be ranked in the same way as pages that are naturally crawled? By labelling trusted feed listings as something seperate and distinct from the rest of the results, then surely these pages can, perhaps even should, be ranked seperately. Most likely, this will mean placing them ahead of the remaining results. Personally, I am not confinced that is a good thing.
In contrast, Google delivers unbiased search results
I have issue with this statement. All SE results are biased, they
have to be. If there was no bias, how would pages be rated? Google, and all SE, give bias to lots of things, like heading tags, links etc, and understanding the bias is why SEOs exist.
The notion that the Google algo is unbiased is a misleading, and in using this as a contrast to Trusted Feed to imply that Google is somehow intrinsically morally superior is not a valid argument. Google decided against trusted feed for a variety of reasons, many of which I am sure are
business decisions, as opposed to morally based, and simply because Google doesn't engage in trusted feed is neither here nor there in regards to either the labelling of such listings, or the validity of such an approach.