Ignoring arguments, aggressive advocacy, "you too"s, asserting that web technologies are great in the face of so much evidence to the contrary and most of all, insisting to use the same inadequate tools for everything from desktop to mobile to embedded.
I've been having the same discussion for six years with different characters now. One thing has never changed - web apps consistently show poorer quality than their native counterparts, especially in performance, resource usage and usability.
The software this community so focused on PR and advocacy is building is not good in spite of the bragging.
And regarding your arguments:
* Java, C++, .NET, Python, etc can claim having ecosystems. JS has a continuously churning collection of libraries. Nothing has been forgotten.
* a lot of Qt developers use it where it makes sense by bulding hybrid apps or together with QML.