However the flip side of the coin in your case is somehow even worse, because people failed to identify the good in the RDBMS and only identified it all with evil, despite then storing their blobs in an RDBMS.
To me, the use of distributed transactions is the smell. If your solution to the problem of a multi-database model is a sticking plaster that can generate even worse problems (e.g. the deadlocks) then it just shows a poor approach to problem solving or allocating enough resource to development.