Usually a plane flies from A to B ... if there is suddenly someone requesting a divert I must consider this as "not normal" and therefore ask for the reason.
There could be something I can help you with and although I'd expect that in that case you'd ask for it perhaps the less-than-glowing reputation (false, of course
) of us spanish controllers has made you hesitant to do so.
Another possibility to consider is that your plane has been hijacked (although I haven't seen a single one in my career) and you can't change your squawk so I'll have to ask... in this case evasive responses have as a consecuence that we would have to notify our supervisor... and if we weren't practically bankrupt you could have to jets at your side just because you didn't want to mention your passenger needed a toilet break.
In any case "for operational reasons" is fine with me but as mentioned on other posts that doesn't ensure a parking place at your new destination.