Well, ever since Disney opened Main Street USA in Disneyland our view of the past has been with decidely rose-colored glasses. There's a book called "The Good Old Days, They Were Terrible!" that points out a lot of these inaccuracies that we hold for the past. From political corruption to food recalls and more, it all happened a hundred years ago.
That said, I do like the daring of design of a lot of the classic coasters, among them the Coney Island Cyclone, which to me still packs a terrific punch. However, my first trip out to CI alone was a bit unsettling, but I was ultimately safe and sound. It was shocking to compare the reality of contemporary Coney Island with the Coney Island of my imagination.
As for preservation efforts, seeing the Thunderbolt was very sad, but it would have been an enormous undertaking to rebuild it, and the support for it just wasn't there. If they built a replica in Times Square, it could be a big hit, but out in C.I., even the Cyclone rarely has a line when I go out to ride it.
The dichotomy we have is the desire to preserve the past while enjoying the guilty pleasures of the present. We want the best of both worlds, but as you pointed out with a few shocking examples there were things in the past we would be better off to just forget.
I think parks like Kennywood have a nice balance of keeping pieces of the past but also keeping up with technology whenever possible, albeit with a lesser budget than some of the mega parks. Even Lake Compounce, our nation's oldest amusement park, took a great step forward with the opening of Boulder Dash this year.
If EVERY 20's park had a visionary team with big pockets they could reinvent themselves to do the same thing, but alas that is not the case.
In the next years we'll see a lot of battles over these very issues, but the "right" individuals with an appreciation for the past but an eye on the future could make these old parks s挀挀攀猀猀昀甀氀氀礀 琀爀愀渀猀椀琀椀漀渀 琀漀 琀栀攀 ㈀猀琀 挀攀渀琀甀爀礀⸀ 㰀戀爀㸀 㰀戀爀㸀 㰀戀爀㸀ⴀⴀⴀⴀⴀⴀⴀⴀⴀⴀⴀⴀⴀ 㰀戀爀㸀∀夀漀甀 栀愀瘀攀 琀漀 猀挀愀氀攀 愀 氀漀琀 漀昀 氀椀昀琀 栀椀氀氀猀 琀漀 挀漀愀猀琀 攀愀猀椀氀礀⸀⸀⸀∀ 㰀戀爀㸀 㰀戀爀㸀䨀愀猀漀渀