When I was a kid I used to visit the roof gardens at London Airport frequently. In post-war times the thrill of seeing aircraft was enjoyed by hundreds, if not thousands, of people. As in my case, many kids were taken to airports by their parents and it was an exciting day out. Now, flying is an every day occurrence for many people and the thrill has gone. Just about every aircraft now looks like every other whereas in those far off days of Avro Yorks, Argonauts, Dakotas, DC4s, Constellations, Stratocruisers, etc., there was great difference between the types which made identifying them great fun.
I can think of no reason why airport authorities should provide facilities for spotters especially in these times of financial restraint and greatly increased security. What are spotters going to bring to the airpport apart from the entry fee and clogging up the already over crowded infrastructure?
I'm sure others will have different opinions but it is a subject which has been discussed at great length on here and other forums.