As somebody who is interested in Scrum but hasn't yet had a chance to try it, I've been paying attention to the various experiences people are having with it.
I've been noticing something for a while, but I didn't really realize that there was something bigger going on.
I call that phenomena "Scrumbut". It shows up in the following way:
"We're doing Scrum but..."
I'm not a strict methodologist - a specific methodology may need to be adapted to a specific situation. But most of these are anti-scrum rather than modified-scrum.
That this phenomena exists may not be news to you, and it wasn't to me. But what I realized this last week is that scrumbut has led to another phenomena...
Namely, it has led to scrum being a naughty word. Managers are working with groups that say they are doing scrum, and then when scrumbut doesn't work, they decide that scrum doesn't work.
How to approach this? Well, I think you need to advocate specific principles rather than advocating scrum. If you tell your management that you are going to be "ready to release" on a monthly basis and that they get to give feedback on what has been done at what to do next every month, I think you will likely get a better response.