You say this like downloading roms is a mere "preference" but in reality pirating games is a purposefully deviant lifestyle choice that is an affront to all good $2000 game-buying butter fatties everwhere and should be stopped at all costs.
I sense sarcasm.

But...To some extent, that is true, but as a guy who's actively involved in game publishing/marketing, it's not always the worst thing when an obsolete title is 'pirated' or copied. Only a small portion of the games you will see today will ever be considered for a re-release, and that being the active franchises or popular titles, like Final Fantasy or Sonic the Hedgehog. But why haven't gems like SNATCHER even been considered for a re-release? And why haven't titles like Castlevania: Symphony of the Night been re-released considering their demand and popularity? Some companies have complicated marketing tactics or standards.

Many games like the PC98 titles and other obscure platforms or consoles are emulated without any concern for profit loss, but so are many consoles. A considerable ammount of NES publishers/developers are out of buisiness or have been bought out and so many titles have been overlooked or are no longer available (the source code could be lost or something of the like) so that hinders titles from being re-released. Although getting back of some of the titles I mentioned, some games like SNATCHER are probably overlooked because they failed the first time and lack an efficient following to allow the franchise to thrive in western markets where it's popularity is considerably less compared to it's overseas counterparts.

Let's take FARIA, for example. It's a great game, but was overlooked, yet, it has never and I doubt it will ever get a re-release, so the only option is to download.

Also, someone mentioned earlier that alot of games that are revamped sell better, and that is true, but not always. Alot of games have been re-released for GBA and nobody cared (like Aero the Acrobat, etc.)