I found people opposed to Listeria lists (in article namespace) for two main reasons:
Thanks! This is very helpful for me.
The wikitext overwriting is a good point and it is easy to understand that this leads to confusion.
For handcrafted lists: For now, we only have some rather vague ideas how to supplement lists with custom data, but it is something that turned out to be very important for users and I'll continue working on this.
Jan