If I enjoy a good burger, when I'm done, it's gone. The money I spent and the time I had enjoying it are gone. But that doesn't lessen my enjoyment.
I've been happier since I stopped thinking about my gaming progress as some monolith thing I need to keep. I have a crazy game of FFVII saved on a PS1 memory card somewhere with all kinds of stuff tweaked out. Will I ever get it out again? Not likely. It ultimately doesn't matter. It could be the same as my character being wiped from an MMO. But did I have fun working toward a potentially stupid goal in the game? Sure. I did at the time and that's what matters.
Like most things in life, the journey is more important than the destination.
I'm also not aware, in the history of MMOs, of a server going down so catastrophically that it completely lost characters and their progress. Realistically, you'll likely move on before the game passes away.
I also don't see lost progress as a good argument against sub vs F2P MMOs. If it's possible for one, it's possible for the other and probably more likely for a F2P that can't sustain itself.
I played WoW for a few years and spent a chunk of money every month on it. I walked away from it but I don't feel that it was money wasted any more than I feel money I spent to see a movie once was money wasted. I spent that money to enjoy something and I did. No regrets.