We allow them at our events and tournaments. We've got a group of around a dozen or so who flitter in and out and nobody has ever expressed any desire to not allow them while many of our players seem puzzled by the ban on them elsewhere. We're not gonna give you something you can't use at one of our events at a later date. So yes we use them in our events in which prize support is available. However if other areas don't want to that's their business and they're entitled to their view. Best thing to do is to announce promos are allowed at an event well in advance. Also if anyone I play asks me to take my promos out I will and I suspect others in my area would do the same.
I use them in casual play as well and see them played in casual play. I know of at least two friends using Rain Cloud and Staff of Storms in Air Wizard books. I know pretty much everyone who has Alter of the Iron Guard puts it in a Priestess or Warlord book. I've seen Fire Elementals get played a few times and I fought a Temple High Guard before. I have a now that I think of it promo heavy Anvil Throne Warlord book with 2 Bloodwave Greatbowmen, Alter of the Anvil Guard, Critical Strike, and Vorpal Blade.