The nature of cryptocurrency is volatile so definitely investors will complain. Perhaps, things aren't going the way they want it. Its all about patience though sometimes complaints lodged by investors make developers speed up and work efficiently.
yeah, investors are complaining maybe because they feel the way the project team works is not so good or very slow.
and i think complaining isn't so bad if it's not too much. as you said, complaints raised by investors will make developers speed up and work efficiently. and of course it will be good for the development of the project.