I use Rails, but also Elixir, and in the past Java, .Net, and many other tech stacks.

In my experience all large or very large scale apps upgrades (and I've done quite a few) are complicated in a way or another, no matter the stack. Technical debt stacks up in subtle ways (dependencies get obsolete, a specific feature used the framework in unusual ways, stuff can be rewritten with more built-in framework features etc).

I don't see how this article would give Rails bad publicity, personally; I'll add that the advice they provide is pretty much what I would recommend for any tech stack too.