Well, you can use a non-informative prior. And that's the correct choice when you genuinely don't have a better option. But you should always be able to justify that, and that in turn requires deep domain knowledge....which leads me to....
> The whole problem we're facing is that it requires too much domain knowledge and detailed analysis to dismiss results that are actually just noise.
....this is in no way a "problem" that needs fixing, by allowing shortcuts that can easily be hacked. Rather, it's a factual statement about the difficulty of drawing correct conclusions, in low Signal-to-Noise-Ratio domains. Whether you use p-values or not, and whether you use Bayesian methodology or not, you cannot get around the need to understand the data you're working with. Bad p-values are worse than none, since you have no knowledge of what error rate they actually achieve in the long-run.
> Bayesianism has no substitute for that
Yes it does. It's called Bayes factors. But as I said above, I completely disagree with your view of what a p-value is for.