Another way of phrasing it (which I remember being used in the context of Microsoft's API): "software sharecropping."

I have no data to back this up, but based on my own experience* I think there are differences in the nature of communication between cell phones and radios (CB/Amateur/business/etc.).
Cell phones being full-duplex, people are more likely to talk over one another, as they do in face-to-face conversations, which means you have to be listening while talking. With half-simplex radios, on the other hand, you're either receiving only or transmitting only, which seems like it would make it easier to "compartmentalize" the activities in the brain. Again, I'm just hypothesizing. Also, on the radio, long pauses in a conversation are not on acceptable but frequently encouraged (to listen for any other stations to want to join the conversation or use the frequency). This, coupled with the necessity of coordination would seem to have the effect of generally slowing down the pace of the conversation, and freeing up more cycles in everyone's brain.

*Granted, I'm definitely biased on this topic, being a ham radio operator who regularly talks on a mobile radio with several other hams while driving to work in the morning. I do try to take sensible precautions, though; I don't talk and drive if the weather is bad, if visibility is low, if I'm trying to navigate in an unfamiliar part of town, or if I'm merging or performing some other delicate maneuver.

I actually asked a police officer about this subject once. Specifically, I asked if they received any special training on how to drive and talk on the radio/phone at the same time. His response was, in effect: No, there's no special training, but witnessing on a daily basis the deaths, injuries, and carnage caused by careless driving serves as a strong motivation to exercise caution while driving.

In the US, at least, the regulations (FCC regulations Part 97.113 in the US) prohibit "communications in which the station licensee ... has a pecuniary interest, including communications on behalf of an employer..."

Viewing a web page that had a few ads over a D-Star or packet network is not a violation, but sending an advertisement, or solicitation would be against the regulations.

The biggest impediment to using the Internet over ham radio is the prohibition on encrypted content. So sending a PGP-encrypted message or viewing a website over HTTPS would be against the rules.

I'm a techie who tends to avoid products from Microsoft. However, I also don't consider search engines to be products. Google doesn't earn any money from all the web surfers typing "facebook.com" into the Google search window. Its primary business is selling audiences to advertisers. When you use a search engine, you're not a customer, you're the product being sold.Given Microsoft's history of defending and promoting their products, I figure I'd much rather be a Microsoft product than a Microsoft customer.