Thanks for the answer.
I agree that Profiles were quite complex, however, <Resource../>* element is rather simple and IMHO it does allow 
defining alternatives. I agree that all requirements that belong to the Resource element must be satisfied but if we 
define multiple Resource elements they should represent alternative requirements. Otherwise this is not reasonable 
because a conjunction of conjunctions is just a conjunction of all elements, e.g.  (x and y) and (z and u) = x and y and
 z and u.
Regards
Ariel

Ranges allow specifying alternatives to some extent in JSDL 1.0. (But I think not the exact example you raise.) 

Expressing alternatives is important but it has consistently proven too complex an issue to settle to everyone's 
satisfaction. The issues had more to do with semantics rather than keeping the schema simple.  Profiles were introduced 
as a way to define alternatives but were considered too complex (in particular their substitution rules) during the 
review at GGF13 (Korea) and were removed from the specification.

The later change from <Resource../>* to <Resources../>? does not affect things because the ability to define multiple 
Resource elements did not allow for alternatives. (All Resource elements had to be satisfied.)

Finally, other specifications, such as WS-Agreement, have defined operators to express alternatives over XML elements. 
It is possible to combine JSDL with such specs (without necessarily taking on all the extra framework they define) in 
order to specify alternatives. So it is not clear to me the advantage of duplicating the definition of such operators in
 JSDL, at least not in version 1.0.

Thanks for your comments.
Andreas