It seems to me that defining this space could be admirable foresight in the (perhaps unlikely?) event that government begins to deal more fiercely with the known abuses of big business and the stock market. (and that, is a potential argument in its own right: let's postulate that there are people out there who consider this whole area pretty toxic)
So, as things stand, the status quo is strongly reinforced, and being extremely toxic is strikingly rewarded. In the event that this never changes, there's not a lot of place for a Long-Term Stock Exchange or anything like it. That holds even while the status quo, being 'extractive', begins to do serious damage to all the stuff we like and care about. So long as the rules favor toxicity and are written by those who stand to gain by it, this proposal is a joke.
But we are also postulating that there is reason to believe such 'extractive' behavior has consequences: call 'em externalities. There's plenty of history on how business can continue that way, even to the point of open warfare, murder of strikers etc. so we know there's motivation to cling to 'extractive'. But history also tells us there's a limit, and societies can turn against this sort of thing in whatever form it shows itself.
(side note: I spent part of yesterday trying to help Amazon not be toxic. I got an LED light being sold as a light therapy tool, $40 or so price but might only be a few bucks worth of LEDs, and I did not order it. Someone's using my name and address, with their own email and credit card, so they can review things as me. It was very tough to get the situation understood by Amazon. Yet, the product reviews had already been frozen for suspicion of fraudulent reviewing, and the product was fulfilled by Amazon and was literally #1 in its category. This is a form of toxicity that leads to Amazon's brand being garbage because you can't trust a thing they say.)
In the event that government changes its approach and begins to deal more harshly with the abuses of big business, which is far from unthinkable, this Long-Term Stock Exchange and seeking to comply with it might be a useful form of virtue signaling by companies that are trying to avoid being targeted as bad actors. And the requirements of the LTSE could track the legal requirements by government as they develop, making the exchange a 'safe haven' and public show of good faith.
The contrast with what you have to do to please current stock exchanges and those who follow them, could not be more striking. It's become very obvious that shows of BAD faith (by certain political standards) are required by the existing investor audience, which seems correct in believing that right now companies are held to no consequence other than beating other companies in making money by any means, full stop.
If that IS stopped, the meta-market (market of money holders seeking markets) would be hot to find a place to invest that was more safe from unwanted consequence.