Ok, so one more message from me in this topic, given Mark's request:
Mark, I like your previously mentioned exhortations not to shoot down ideas without an affirmative reason that they are bad or might actually hurt something or be bad for the product. What gets my goat are messages that say, "Why do we really need this? You can just do [xyz inconvenient workaround]." There are almost always workarounds. Heck, there's a workaround to groups.io! Why do we need it? Just create your own email list!
The answer to those kinds of comments is always the same: "Yes, there's a workaround, but we are just trying to make things better, make mods' and members' lives easier than having to do the workaround, and the suggestion doesn't hurt anything." It's like rinse-and-repeat.
I think arguments against a suggestion are fine if they describe why they could actually have a negative effect.
And I have one more pet-peeve subservient to this: "I'm not arguing against this" followed by the above ("but we don't really need it" yada yada).
Messages are the sole opinion of the author, especially the fishy ones.