I understand the gist of your major points, and I cannot argue against them with anywhere near the eloquence with which you make your case. In the larger scheme of things, at the end absolutely nothing matters aside from the people and loved ones in our lives, and where we and they will spend eternity after death. All of our wordly possessions and even life's accomplishments amount to little more than a hill of beans in comparison. That said, everyone needs a diversion - a hobby or something of specific personal interest which holds special meaning in our everyday, sometimes mundane lives.
Collecting stamps, golf, gardening, theme parks (travel), or a myriad of other activities aren't what ultimately matters, but they do serve to make our days far more pleasant, enjoyable, and often rewarding. Without question, people tend to be emotionally invested in a specific interest; Thus, we care about the Disney theme parks, it matters to us what happens to them, and we certainly have (often strongly, sincerely held) opinions on the matter. We don't need expert knowledge of design (or business, etc.) to make a valid (if laypersons) argument about theme parks. Indeed, after sometimes years of observing and following the industry, at least some degree of 'expert' knowledge can be demonstrated in posts by several members on these boards.
Disney may place remarkably little weight on the opinions, desires, and requests of its (long-time) customers, but in no way does that suggest we should not make our voices heard. We should never be so ambivalent or irresolute about anything in life; Actually, that is in large part what is wrong in this nation. If something bothers you, upsets you, or just isn't to your liking or satisfaction - then by all means say something. You don't just sit back and let things happen. There is nothing wrong with taking a stand, even if it is on a topic which, in the end, isn't what really matters in life. We must keep our priorities straight, to be certain, but we can enjoy the Disney theme parks (in a mentally healthy manner) as part of a richer, more fulfilled life.
Sarcasm and hyperbole aside, the "bar" by which we judge Disney in 2014 may well be difficult to define, but we can illustrate with sold, concrete evidence and examples a very real decline in Disney's own standards over the intervening years. It isn't just nostalgia or a longing for the past which clouds our judgement; The bar has literally been set lower than it once was.
You seldom literally hear of Space Mountain being so 'beloved' either, but that is because Space Mountain isn't on the endangered species list. If a (reliable) rumor came to light about it being bulldozed, then you most certainly would, just as you do for Maelstrom or the Carousel of Progress.
There is also a valid point about what is replacing Maelstrom, and its thematic inappropriateness for World Showcase. You won't see the same concerns over removing Indy or LMA, partly due to the attractions themselves, but party due to what (presumably Star Wars) will take their place.
Whether we agree or not, arguing that something should be preserved purely for nostalgic reasons is a legitimate viewpoint. In the case of Maelstrom, however, there is far more to it than just nostalgia.
