I arrived at the same place that Kent Weare arrived at here.
In my case MSDTC was also configured based on Microsoft’s recommendations. I also used the DTC tester but in my case the test completed successfully.
The environment that I was working on had been hardened using the security wizard. We checked all the services running on the SQL Server and everything that was required was running but when we ran the wizard we saw that DCOM was missing.
After enabling Distributed Transactions I was able to successfully configure the BizTalk Group and RunTime.