Some companies have no money to buy EJB server. In such a case, RMI can be used to build distributed system.
Talk the friends around you. You will know how expensive the EJB server (such as Weblogic and Websphere) licenses are. I cannot post such information here.
As a system architect, he/she needs to choose most suitable technologies on the bases of business model, budget, and developer's skill set. In any case, EJB cannot be ubiquitous( universal in your words).
Actually, many EJB projects are abusing EJB technology. Technically,
one should ask how many DISTRIBUTED TRANSACTIONS there are in the system before adopting EJB technology. EJB is too expensive, both
econimically and technologically. EJB makes the life of the developers much easier at the expense of taxing resources heavily.
For some small distributed system, RMI is still a good choice.