Blah, blah, yadda, yadda, yes we know. Still doesn't make it any more ethical to take away from the hard work people put into these games. Years of creativity and effort only for people to cheapen it by making it free.
The people that are into this do it to play souped up versions of the games they love. And the roms they are using are ripped directly from copies of the game many times (hence someone had to buy it). I used to copy cds, dvds, etc. Why can't people rip a game from a cd or cartridge and play it how they want if they own it?
I will admit, where the piracy comes in is the big websites that offer the roms, and those get shut down all the time. Even then, most people pirate the old stuff (SNES,PS1, etc), because most new stuff is unplayable without a decent rig. And companies are still selling old games like hot cakes so I think emulation barely makes a dent to the industry. Not anywhere close to making an impact on the market like PC piracy.
But the emulators themselves are really not anything bad, and I don't think the people making them profit off or get much out of making them aside from self satisfaction.