Two hints:
1) Don't "fish" for things - that's passive-aggressive.
2) Don't start with the premise, "To disagree with me, my opponents are likely ignorant." It is only a half-step off from, "My opponent must be crazy or stupid," and is effectively ad hominem - it is based on the person arguing, rather than the content of the argument. In addition, is assumes the correctness of your position, rather than establishes it through evidence or reason.
Can you please not read my posts in the least favorable light possible? If you really don't like the questions I'm asking, why not just ignore my questions? Why bother calling me passive aggressive and accusing me of making personal attacks?
I know nothing about your games. I have no way to know if you knew about this rule. My point is that your response to OP's post here is alien to me:
Pretty much this. The positioning of the OP gave me that "no one can stop you" vibe, which I just have a problem with in the context of cooperative play.
If it had been presented as, "Hey, can't get quite what you are looking for? Remember that, within the rules, you might be able to modify a background to get what you need! Talk to your GM about it!" and the whole discussion becomes different.
Framing matters.
Let me rephrase: Your reading is so far off from my reading that I would like to understand how you arrived at that interpretation, and I was asking for why that's your interpretation of both OP's post and the custom background rule. In my mind, your second paragraph is not significantly different than OP's post. I just don't see it and I am confused.
Yes, one way I could imagine having this reaction would be to have no knowledge that the rule exists and suddenly stumbling across this post telling people that it's ridiculous that people don't know that this is how the rules read.
I do not think that about you or your game, but I do think that a DM who wasn't aware of the rule might react this way to being told that it's RAW. That's why I specifically asked why the way I did:
Why is background customization really any different? Is my difference in reaction that I already knew about the rule and we have played that way since 2015 or so when we discovered it?
No, I'm not trying to say that you
must be reacting that way because you're stupid and I know everything. I'm saying that
I don't understand the resistance to this rule and
I don't understand this reading of the first post.
From my view, I've asked you for an explanation and you've responded, in so many words, "Stop attacking me."
If I've offended you, then I apologize. I am not attacking you. It feels to me like you're twisting my words. Do you think I'm sea lioning? That I'm trying to say you must be stupid? I am doing neither. I genuinely do not understand.