Firstly, I'm not asking this question to judge any member's freedom of giving downvotes nor am I judging their decisions. However, I've been wondering why I'm sometimes getting serial downvotes to my questions which takes much interest, get answers and comments such as this one with 3 downvotes
The StackExchange explains downvotes as 'This question does not show any research effort; it is unclear or not useful'.
However, the aforementioned question (and the priors encountered the same issue if it's an issue) includes research effort and clear (that would be subjective to decide as an OP whether it is useful or not).
If you provide a possible explanation, that might be helpful for the ELL and English Language StackExchange too because I can self-filter this kind of questions of myself and try to reach answers on another platform maybe. However, that is impossible now as I don't see any problem with it.