I don't have any issue with asking CMs if there is any remote possibility that they can help with something
IF my reason for needing/wanting to ask was not entirely caused by my own actions/decision.
But in the situation described in the OP, the reason for asking is because despite knowing you had a coveted FP and were lucky to have it, you decided to go ahead and prioritize something else for that same time frame instead. That was your choice.

We all have to make choices when we're at WDW. Usually people simply cannot do everything they may want to do (Unless they are staying for quite a long trip.) and so they choose what's most important to them of the options available. If two things you'd like to do are only available at one time, then unfortunately, you have to either choose one of them, or keep working to try to secure new FPs or ADRs on your own for the other activity. I view FPs and ADRs as a guest's responsibility and I don't think personal responsibility goes away just because you are at WDW.
And I don't think this has anything to do with regional differences. But if I did, then I'd say folks living in/near big cities would be even less inclined to get on board with the idea that one person in the sea of humanity that is a big city should try to get someone to rearrange things for just them. I mean, imagine if we were talking about trying to get last minute adjustments made to a ticket for a showtime or a reservation for a popular restaurant. Everyone else did the hard work to secure those tickets/seats/tables. And if they had them, they didn't choose to try to keep alternate plans at the same time and hope they could sweet talk someone into letting them switch their times for one of those items at the last minute. I live quite near a city, too, and I imagine if something similar happened in the city, the response of people nearby hearing such a thing would "Heck, no! (Word choice altered due to the family nature of this board.

)
Plus, having worked in a customer service position in my college years, I know how it feels every time someone comes up to you asking for something you cannot do. It feels kind of crappy. And it's a bit stressful, because you don't know how they'll respond to hearing "No.". Because some adults really are worse than toddlers when it comes to being told they can't have something, and no CM knows ahead of time which guest will take the "no" gracefully and which will pitch a fit. With something like this, if word got out that you could simply opt to talk to a CM to get yourself a prized FP, it would be bedlam with everyone hunting down CMs to do the very same thing.
So while I personally wouldn't have said a word to you about it if you hadn't asked, if I overheard the conversation between you & the CM, I would definitely have raised my eyebrows in surprise and walked away shaking my head over the situation. I wouldn't call it "pushy". But I would call it "entitled". Sorry.
(Now, had you been new to all of this FP/ADR/WDW planning stuff, and you simply made an honest newbie mistake, realized it, and apologetically went to a CM to find out if they had any advice on what you might do to correct your mistake, and they offered to try to help you out as a bit of extra Magic, I would feel very differently about the entire situation. I would have definitely empathized with you in trying to figure out the world of WDW pre-planning, and I would have thought it was sweet that the CM found a way to help you.)