I think this train of thought is just another case of coding snobbery.
If a behaviour or plugin does everything you want it to, then coding it from the ground up is not only a waste of time, but goes against modern programming.
Code is meant to be reused as much as possible, and using behaviours and plugins is no different to using existing classes/functions and libraries, either as they stand or adding to them for your specific purpose.
At the end of the day, people are using programs like Construct to write games, and whether it's because it's faster to develop or because they don't know how to program at code level, there will be code snobs who will say that it's lesser than using something like C++, even though C++ programmers will be using built-in libraries and external libraries for most of their calls (which of course were written by someone else, lol)
If a game works well in both idea and performance, then it's irrelevant how it was coded.
Java used to be ridiculed years ago, but over the last few years it's been instrumental in the rise in mobile phone games, and it culminated (in my opinion) in a game like MineCraft showing just how irrelevant a specific language is.
Just remember, generally, if someone is saluting a specific language/tool to the degree that they ridicule any other method, then you can be sure that either:
a) It's the only language/tool they know how to use
b) They chose the hardest way to program something so that they could prove to themselves how great they were (which means they are lacking confidence in general).
As someone who started programming in 1982/3 (ish) and has used Z80 machine code through to C++/C# with everything in-between, and enjoy using software like Construct/Unity/Stencyl etc, I'd never judge a game by how it was written.
The final result is all that matters.
But then I'm not a snob in any aspect of life, and some people can't be anything else but a snob, lol.