I think it's possible, even likely, that tests designed for optimum situations don't reflect real world use cases in any way. That's why it's important to know who the testing companies are. What are their true motivations?
I agree with you that intentions should always be investigated. And almost always these kinds of things are simply self-advertisements for the services that such companies provide. To get attention, they publish something click worthy. Which usually means something about Apple
That said, after reading a bunch of Cellular Insight's blogs, there doesn't seem to be any particular agenda, except maybe to accidentally promote T-Mobile.
As for their concentration on Qualcomm, well after all, most phones do use Qualcomm modems in the USA, and there's no doubt that the current Intel offering has fewer features. Those are facts they can't change.
Moreover, they're not alone in concentrating on Qualcomm. It seems that's pretty normal. E.g.
Not All 4G LTE Modems Are Created Equal - Forbes guest article by
Moor Insight & Strategy
Maybe they did it for power savings.
Maybe not.
Everything I've read says that Qualcomm is best at power savings, partly because it can spend the least amount of time online to download the same amount.