Because at least some of those missing prerequisities are incredibly obvious? Granted, most dancers just don't think or learn properly.
Say, a workshop on boleos — I saw plenty of examples of bad stability and insufficient free leg fluidity. Arm leading, plenty of stiffness everywhere, et cetera...
It is also because prerequisites are not easy to frame in the first place. They are almost always expressed in one of three ways:
1. "Requires Tango
N or higher."
N is a class level at the studio giving the workshop or hosting the festival offering the workshop, or at the home studio of the person leading the workshop – something like "4" or "IV" or "401." As the only requirements to advance in class level are paying money for and sitting through all of the previous levels, and as there is no testing process or graduation system to hold anybody back if they haven't absorbed the material (that would be commercial suicide, and I've never seen a studio do it), there's no guarantee of "qualified" dancers having the technical skills that Tango
N is meant to give in an ideal world. The workshop leader might know some of the students and guide them toward or away from the workshop, but in small places, the students are likely to have come from other small places all over or the leader might be a visitor, while in large places the leader is inevitably a visitor; so, the whole thing is double-blind.
2. "For [
skill level] dancers." This [
skill level] is something like "all," "beginner," "beginner-intermediate," "intermediate," "intermediate-advanced," "advanced," or "master." This relies on self-evaluation, because these things don't have any objective definition . . . most people overestimate their skill level. Once again, a workshop leader could in theory evaluate level and guide students toward or away from the workshop, but in reality it's double-blind, so that almost never happens. Occasionally, the leader attempts to work around this by expressing [
skill level] in years, but that rates nothing useful, as dancing badly without correction can mean that the real difference between 1 and 20 years is 19 years of mistakes to erase – an effect amplified in smaller communities, where lack of exposure to regular instruction, broader concepts, and many dancers imparts the mistakes of an entire pedagogically inbred group.
3. "Must be familiar with [
list of vocabulary]." This at least tries to itemize what's needed instead of using bought-and-paid-for class level or self-assigned skill level. The trouble is that it considers only vocabulary, which isn't half as useful as technical basics for judging capability. The workshop leader could
say (to use the boleo example) "Requires supporting-leg stability, free-leg fluidity, considerable flexibility, and having internalized lead-follow with the core (can you dance arms-free?)," but that (1) won't fit in a little box or table that has space for "Tango IV," "Intermediate-Advanced," or "Ochos and Rebotes," (2) is another form of commercial suicide because we live in the TL;DR era where text longer than a few words is ignored, and (3) still depends on self-evaluation. And in small places especially, technique isn't seen as a thing to learn in itself . . . there's no instructor leading regular mirror drills, and people get obsessed with steps because they have four partners to dance with and find the same steps get boring.
Honestly, I think that prerequisites are hopeless for workshops, and that workshop leaders are doomed to spend some, most, or all of their time teaching missing prerequisites instead of the workshop's nominal topic. Giving them the power to kick people out? Commercial suicide again! So, they must shut up and go with the flow.
This is especially true in smaller communities, where
nobody might be ready for the workshop's intended topic, and where the workshop leader is a visitor whose paycheck is thanks to that community's invitation and thus who doesn't dare get too demanding, much less show frustration. In that case, the workshop's supposed topic is just a fancy title, a lot like calling a fast-food combo meal "Royale" or "Gourmet." It's marketing, and a smart instructor knows they'll be teaching prerequisites with the pretense of getting to a topic they'll never get to. If they're charismatic and supportive, they'll be able to give everybody who attends a sense of value, though of course a few will grumble about not getting around to the topic. If they're business-savvy, they'll also try to negotiate follow-up workshops or private lessons that do get around to the topic.
This isn't meant as an attack on small communities – community size is just an added layer of difficulty to a general situation. I remember a follower sacada workshop by Pablo Inza and Sofia Saborido, who are decent teachers, at a big festival in my big city. Everybody present supposedly met the prerequisites . . . but not a single follower managed to execute sacadas properly, and Sofia spent all her time explaining to the followers how pivots and front steps (!) work, while Pablo mostly just joked around with the leaders, because "how to receive a follower sacada" isn't that interesting. I attended with a friend, not my usual partner, and was bored out of my skull, as my usual partner is already comfortable with front, side, and back sacadas in all directions on all sides, and I knew I was leading them correctly, so I was essentially the ballet barre for someone learning how to take a decisive step into my space.
