Earlier quoted context omitted.
Because Flutter would be a nice framework to use if they hadn't decide to bet on a language struggling for survival outside Googleplex. React Native uses a programming language widely accepted, no need for complains.
You said you can't be bothered to learn dart because you want to build your skills in c# etc. As a result the only criticisms you can make are devoid of content: It's not a proper, modern language (what?). It's struggling for survival...
C# was just an example of a language that is actually worthwhile to have on a CV. I could have given many other examples.
Ad Words team rescued Dart from certain death and Flutter it is attempt to come play into the ring.