But this is why we study things?

Here, read for yourself (PDF link)

Glancing at their results there is appears to be a trend and that’s fine.

To conclude, we have provided the first slice of empirical evidence to suggest that autistic individuals may demonstrate a propensity toward object personification and anthropomorphism. It must be noted that our clinical sample was based on self-report (rather than objectively verified diagnoses) and respondents were recruited via convenience sampling – both of which may reduce the generalisability of the findings. However the results appear to echo the anecdotal comments made by autistic individuals. Furthermore, in our review of online forums, we were struck by the distressing tone of many posts (WrongPlanet.net, 2017). Autistic individuals reported sadness and despair when faced with an object that might be hurt or lonely, and several asked whether they might receive “help for their problem”. It will be important for future work to establish the frequency with which object personification causes distress, and if necessary, to identify possible structures for providing support.

This is a very poor take, and it is clear you didn’t even read the abstract before deciding the study is pointless. There is an obvious value in determing not just what traits are shared between autistic individuals and neurotypical individuals, but also determining the degree and intensity.

To use your example, what if the study on drinking water showed they needed less water than an average person? Could that not be valuable, and lead to further research?

This study identified an anomaly. Autistic people have trouble identifying with emotions in other people, but for some reason seem to have no problems doing so for objects. Isn’t that strange? Doesn’t that beg the further question of why? Great revelations in research are built on tiny stones like this.