It's our own fault. If we refused to use the ones that charge then they'd not bother making any more. I've never paid to get my own money out, and nor will I.
I used to like our coinage. Not so much any more though.
Once some thought went into what subject was worthy of a commemorative issue. Now it's all about what people will gush over and rush out to buy in its many differently minted forms.
It's good. Decent edges too, which is often a problem with these due to the weight - it only needs to be dropped once.
The large size is due to the coin being made from 2d worth of copper - 2oz.
Personally I think it's just poor quality rather than an error. If I wanted one at all I'd rather have an unflawed one.
I could be wrong but suspect this post is just a plug for your ebay listing?