Yes this is actually true for a commercial user ...who does not care much ...but there are some users to whom it matters like the Stock Brokers ...I do not know of any online stock
exchange systems being developed in J2EE..
Slight off board .. but the point is predictability
It is said "A real-time system is one in which the correctness of the computations not only depends upon the logical correctness of the computation but also upon the time at which the result is produced. If the timing constraints of the system are not met, system failure is said to have occurred
Hence, it is essential that the timing constraints of the system are
guaranteed to be met. Guaranteeing timing behavior requires that the system
be predictable. It is also desirable that the system attain a high degree of utilization while satisfying the timing constraints of the system."
J2EE servers claims to be predictable ..but are they ???
http://www.mrtc.mdh.se/publications/0710.pdf