When you buy a PC-FX and games, you really have to come at it from two angles. There are a few consoles like this.
On one hand, you want to play games, obviously. The PC-FX is hard to do, for reasons that have already been stated. It's not impossible to enjoy without knowing Japanese, but it does become harder. If you can afford the games that are playable without Japanese, then it's great!
On the other hand, you have the collector mindset. The one that wants something obscure and not well known. Something to talk about and show off to people. This is perfect for that.
The PC-FX represents the last of the "classic" consoles in my mind. The last time that 2D art was the pinnacle of game design. For that reason alone, it's one of my favourite consoles and I'll defend that position until I die.
Seriously, you should try the games before buying. Like them or not, you should then consider whether it's a piece of history that you would like to own, regardless of games and homebrew.
It is a piece of history and shouldn't be forgotten. Thank science for this forum (^_^)/