If these poles have been in use with sanction, permission, or by instruction of management and/or your trainer, I would quit.
Saying that there are worse ways to train a horse is a red herring argument and I despise it when people try to justify something by saying "well, it could be worse, other people do worse!" Person B doing something that’s more objectionable does not mitigate the fact that Person A is still doing something that’s also objectionable.
At the end of the day, who I associate with is a reflection of me: my standards, my morals, my ethics, and my integrity. If I knowingly continue working relationships with people who participate in behavior I find objectionable (even if it’s not to my horse), I am implicitly sanctioning that behavior. I understand that being in this position is a privilege and not everyone will have the resources to be so willing to cut ties. That said, I would not be willing to continue any form of relationship with someone who uses implements like this.
The caveat on this: if they are in use. While it bothers me that they are even around (seriously, if they’re relics of a former trainer who has since moved on or a different era of a trainer’s past that they have grown from and learned from their mistakes, why do they still have them? Either dispose of them or deconstruct them so the poles are not just wasting space…) I do think it is possible that people go through phases in their education and their understanding so just because a professional used inhumane training devices in the past does not mean that they have not come to conclude that doing so was a mistake and do not do so now.
If you cannot identify for certain if they are in use, the advice above is solid. Observe, make note of what you see, and weigh the benefits of the position against the horse care and training.