I don't agree with that analogy because games are a set price. If you pre-order, you're paying the same one-time price, but you don't get a chance to learn about the product before it releases.
Plex has a subscription service. Whether you pay the subscription fee or buy a lifetime pass, you're getting the same product that is already available for free. You can test it out, decide if you like it, then if you want advanced features, pay the extra cost for it.
True, it could turn to shit later. But a one-time payment is far cheaper than paying monthly or annually forever. I'm saving money AND getting access to the same product.
As I said in another comment in this thread, my Lifetime Plex Pass has already paid for itself. I would've paid more for a subscription by now if I had gone that route. And it has all the features I currently want, so I'm pretty happy with my purchase.