I suppose nobody is going to tell the poor newbie that playing a version of mame that plays these games violates the mame liscense.
Also the only way these games can be played on other emulators is by running hacked versions of said emulators as it violates their liscenses as well.
Long story short..... the games are too new, you aren't supposed to be able to play them period.
the money isnt really being made on arcades atleast in the US, most of the money is being made from console ports.
And how does that make any difference? If you've pirated the arcade roms you obviously aren't going to fork over the cash for the ports. I.E. it still hurts the industry. And if anybody needs money, it's snk/playmore. They are on the verge of going bankrupt on any given day.
Actually, it seems that the old games are more popular. Here is Midway's Arcade Treasures for PS2. It is Volume 1 of 3. The details:
Arcade classics from the 80's, such as Gauntlet and Spyhunter
Target audience: 12 and up, classic gaming fans
Type of game: Arcade compilation