I think one of the reasons politicians can be bought so cheaply by interest groups is that the opponents of the interests groups have practically no money. The interest groups don't need to spend a ton as long as they spend more than their opponents.
The linked post talks about the effectiveness of AIPAC but fails to mention how much is spent by say, Palestinian interest groups. Perhaps there's a good reason for this: do Palestinian groups have any money to spend on US elections? Try fundraising in Gaza right now.
Likewise, business interest groups have a lot more money to spend on elections than, say, environmental groups. The latter have to beg for small donations from individuals just to stay afloat. Thus, it's relatively easy for business groups to outspend environmental groups. To win an auction, you just have to be the highest bidder.
In my opinion, this article looks like a straw man argument, and the author appears to completely misinterpret "This is not the computer for you."
Such a statement needs to be understood in the relevant context. It's not intended to discourage kids from buying a Mac! Rather, it's intended to rebut critics who are already Mac owners and who scoff at the MacBook Neo technical specs, such as RAM. The computer is indeed not for them, people who can already afford a MacBook Pro, for example. The point of "This is not the computer for you" is the opposite of how the author characterized it: the point is that the MacBook Neo and its specs are actually fine for the people who are going to buy one.
For some strange reason, the author has invented an imaginary opponent to become offended by. We're supposed to cheer for the kids here, and I see that many people have fallen for it, but the whole schtick falls completely flat for me. The kids were never endangered or discouraged by the reviews of the MacBook Neo.