One of the common problems with many accelerator programs is that they are run by people who are not themselves experienced founders. Not surprisingly, their advice is often counterproductive.
Advice IMO is the least valuable benefit of an accelerator. There's no shortage of advice out there, and founders who take bad advice only have themselves to blame (poor judgement).
The negative impact of bad advice IMO is far outweighed by the potential impact of an expanded network, the momentum gained from "rising to the challenge" of an accelerator, and the capital infusion.
(I 100% believe you)
A crazy one I remember was telling a pre-product startup that they needed to focus on defining their brand.
(For avoidance of doubt: this wasn't an accelerator I have or had a formal relationship with, and -- thankfully -- won't be on the short list for almost anyone reading HN. For further avoidance of doubt: if you ever have coffee with me in Tokyo and ask for accelerator recommendations I am likely to observe that plane tickets are cheap.)