Agreed. I built an in-house mobile crash reporting solution even though the commercial options range from decent to excellent because none of them offered self-hosted, nor a way to export your data. We really wanted the data because it's allowed us to determine the cause of crashes and answer other questions that we otherwise couldn't w/o the raw data. There were also privacy concerns, even though in theory crash reports shouldn't have any PII. And we really don't need third parties knowing our DAU numbers and whatever else in any case.
There are finally some self-hosted commercial options in this space, but we've already built our solution and it works well.
The proprietary vs open argument is less important then the argument over where the data is physically held and ownership of it.