That depends on your point of view I guess.
The trouble with arcade boards is that different games running on the same hardware (EG SFII and pinikies) are worth different amounts.
EPROMS are not the most diffucult things in the entire world to copy and shortly after the release of Street Fighter II there were litterally thousands of copied bootleg boards floating around. When you bear in mind that these things uesd to retail for well over $1000 each this was a major problem for Capcom.
So what to do? Simple, encrypt the EEPROMS. Only one problem with that is that the decryption keys are alos stored in some kind of Non-volitile memory on the game board so it's pretty trivial to copy those too.
And thaqt is where the Idea of the "suicide battery" came from. If the decryption keys are stored in volitile memory (ram), then if they remove the chip that contains those keys from the board to try and dump it the keys dissapear and they can't dump them. Brilliant!
"The battery will last for years, who will want to play these games 10 years in he future?" is how the argument went. Well, now it's 10 years in the future - and people still want to plat 'em
In terms of a bootleg protection device the suicide battery was a huge success - it killed the CPS1(.5) bootleg industry stone dead, and to the best of my knowledge there were never any CPS2 bootlegs at all.
Unlike music sharing or P2P game copying I DO have a major problem with bootlegs of software that is actively used to make money. Unscruplous operators would buy bootleg boards at 1/20th the proce of the real thing and proceed to make MORE money than honest operators becasue they could put more machines on the floor. So yeah, two thumbs up for the suicide battery!