This is a linkpost for https://atheistkit.wordpress.com/2017/01/20/we-should-abandon-weak-atheist-arguments-like-jesus-never-existed/
This reminds me of an effect I've noticed a few times:
I observe that in debates, having two (or more) arguments for your case is usually less effective than having one.
For example, if you're trying to convince someone (for some reason) that "yes, global warming is real", you might have two arguments that seem good to you:
But if you actually cite both of these arguments, you start to sound weaker than if you picked one and stuck with it.
With one argument your stance is "look, this is the argument. you either need to accept this argument or show why it doesn't work -- seriously, I'm not letting you get passed this". And if they find a loophole in your argument (maybe they find a way to believe the data is totally wrong, or something), then you can bust out another argument.
But when you present two arguments at once, it sounds like you're just fishing for arguments. You're one of those people who's got a laundry list of reasons for their side, which is something that everyone on both sides always has (weirdly enough), and your stance has become "look how many arguments there are" instead of "look HOW CONVINCING these arguments are". So you become easier to disbelieve.
As it happens, there are many good arguments for the same point, in many cases. That's a common feature of Things That Are True -- their truth can be reached in many different ways. But as a person arguing with a human, in a social setting, you often get a lot more mileage out of insisting they fight against one good argument instead of just overwhelming them with how many arguments you've got.
The weak arguments mentioned in the linked article multiply this effect considerably. In my mind there's like, two obvious arguments against theism that you should sit on and not waver from: "What causes you you to think this is correct (over anything else, or just over 'we don't know')" and, if they cite their personal experience / mental phenomenon of religious feelings, "Why do you believe your mental feelings have weight when human minds are so notoriously unreliable?"
Arguments about Jesus' existence are totally counterproductive - they can only weaken your state, since, after all, who would be convinced by that that wasn't already convinced by one of the strong arguments?
There's a secondary effect, too, I think, where people partially optimize for preaching to the choir (probably why Christ Myth Theory arguments are as popular as they are even though they flout the mainstream secular consensus), and end up using arguments and a tone that no one could seriously think would be even a little persuasive to actual believers.
Those preach-to-the-choir arguments also contribute to this dilution effect. Even the good arguments and the tastefully presented ones pick up some Horns Effect from all the preach-to-the-choir arguments. Everywhere I look, I mostly see atheists creating content designed for atheists, rationalists creating content designed for rationalists, etc., and much less material designed to actually teach or persuade those not already persuaded.