Yes, there are practices among some Roma communities that are harmful, but those are also challenged by Roma themselves. There are Romani organisations out there who fight for change in those communities. Those actually do ask the question why these practices occur, how widespread they actually are and what can be reasonably done to reduce that from happening

So you basically admit that there are problematic behavior in some Romani groups, and that's (one of) the reason for the integration difficulty. So much so that Romani people themselves are trying to change it.
Contrary to most comments here crying racism, you won't find many commenters here saying it's the Romani ethnicity that's the issue, it's the behavior that has gotten them a bad reputation.