Yes that has to be it. It couldn't possibly be because biological research is amazingly difficult, and of the tools we have to study cells (few) we have even fewer to study viruses.
The entire point of gain-of-function studies is that you need to do them in order to confirm a hypothesis about what genes in a virus are actually doing. If you don't do them, you can't know. Knock-out studies aren't enough - you can easily break a certain system, but it doesn't tell you that you actually understand how it functions.
Sensationalist articles like this are incredibly stupid and dangerous to boot. We only have the slim number of effective anti-viral drugs we do because of research like this. How else do you think they figure out which biological pathways are worth targeting to shutdown a virus?
And that's not all: the other side of gain-of-function is of course to try and predict future vectors. Since treating the common flu is usually a losing prospect at the moment, and it takes time to manufacture things, its important to determine if any given species could trivially gain extra functionality which would make it dangerous - since that affects decisions about what strains to grow up for the yearly flu vaccine.