Let's say you've given it the proper consideration, and it's clear beyond the smell of subjectivity that it needs to be flashy stuff, go for it. The point is that this is often not the case, and the argument is to go with boring then.
> The right technologies for a project are the ones you deem to be right, given appropriate consideration of many factors
It's _usually_ difficult to take into consideration all the factors of a new flashy thing. The unknown unknowns. Thus _maybe_ choosing a trendy set of technologies might indicate that the exercise of balance and consideration you were commenting and that I do agree with 100%, has not been as honest as possible.