Beachcomber thank you for listing the symptoms and signs of meningitis and pancreatitis. As an NHS clinical virologist I am well aware of these, so am not in the habit of "bandying [them] about" as you rather insultingly put it.
Presentation of a child with meningitis is an acute medical emergency, and neither the paediatric staff, nurse specilists, and parents, have the reassurance of your armchair retrospectroscope to immediately tell them their child's illness is likely to be viral and thus mild. A considerable amount of medical and technological effort is brought to bear to provide a laboratory diagnosis before any such reassurances can be given. Meanwhile the parents are worrying A LOT, and the child is probably admitted into a paediatric ward which can be pretty frightening in itself. The child will have to have a CT scan, and if safe to do so, a lumbar puncture to provide CSF for the lab. The child will be given empirical antibiotics to cover the serious bacterial causes. Technical or scientific staff will be called in to look at the Gram film of the CSF for the presence of bacteria. Blood will also be taken from the child for multiple other pathology tests, including virology. In less recent times it used to take quite a few days for the diagnosis to be made, in which the child, and the acute anxiety of the parents and relatives, will remain unchanged. Aside from these humanitarian factors, the cost of admitting a child with meningitis is not cheap by any means, and takes up a bed that another ill child could have.
I would have thought that you and the other people posting on here, who have unfortunately seen the inside of hospitals more than most, to at least be aware of what some children can go through in an effort to make them better. Remember that in the pre-MMR era, the scenario above occurred 1,200 times every year in England & Wales, just because children weren't vaccinated against a virus that causes what you blithely refer to as a "mild" meningitis.
On the other side of the coin, here's what can be achieved in a population of ~5m (Finland), which successfully eliminated mumps by virtue of a high MMR coverage >97%...
Number of notified cases
1971: 22980
1997: 0
Absent from school or work (person years)
1971: 650
1997: 0
Meningitis
1971: 6,400
1997: 0
Encephalitis
1971: 160
1997: 0
Orchitis
1971: 1,600
1997: 0
Bilateral
1971: 500
1997: 0
Male sterility
1971: 125
1997: 0
Mastitis
1971: 1,800
1997: 0
Temporary hearing problems
1971: 920
1997: 0
Permanent hearing problems
1971: 25
1997: 0
Thyroiditis
1971: 250
1997: 0
Pancreatitis
1971: 80
1997: 0
Myocarditis
1971: 30
1997: 0
(Peltola, H., Davidkin, I., Paunio, M. et al. (1999) Indigenous mumps eliminated from Finland (Abstr 158G/HS). 39th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC). San Francisco, CA, 26?29 September.)