Like all things, we need balance. This is a good argument against guilds, but there are positive aspects of the system too. Imagine a world that was truly a free for all -- one in which there were no trusted authorities in any field. I believe such a society would quickly devolve into a dystopia and collapse.
From my perspective, the big problem is when there is no competition among guilds and the guild leaders wield disproportionate societal power. That is how you end up with oppressive oligarchy, which honestly is a reasonable description of the global order right now. My hope though is that we are better able to organize and compete against the current oligarchic order.