Comment by t43562

In some cases it's just because they think that any "missing thing" might be the one that causes customers to reject the offering. So they "must" have everything. It's the lack of knowledge that's the problem and they don't feel that they're going to get more than one chance/feedback cycle to learn from.

The product managers proposing things have their reputation tied up in them so a major feature is a chance at fame for them.

It's as if everyone gets "a turn" at using the development department once in a while and they want to make the utmost of it, knowing that the instant their feature is "finished" the spotlight will be gone from them for months.