I think this is ok. They attempt to add a barrier here, with the attempt to increase the quality of the issue suggested. This may not be the only goal; one may be to have fewer issues raised in total. But there may be several advantages, as well as disadvantages with that approach - it is simply a trade-off.

In particular when I maintain an open source project, I have a lack of time in general so I need to move quickly. I actually don't mind issue discussions on my project, but people can not expect me to invest a lot of time into managing all of those; whether this is a discussion or an issue directly, is not so important, but I know that some project owners don't like open issues that remain open for years. It is kind of a difference in philosophy here.

One trade off is that I am not so likely to get involved in such a project. I may start a discussion, but in general I am very chaotic and may never follow up on discussions I started, simply due to lack of time, too many things to do, forgetting too much too (I do keep notes locally, but these files just keep on growing!).