Before I say anything else, I want to very strongly recommend that people abandon abandonware based only on the fact a modern indie game will probably be less hassle to obtain, install and run. You will also only be able to talk to the one other person on the internet who is also playing this game and you don't speak their language.
Now with that out of the way, I'll suggest that abandonware can be a slippery slope because I think you can apply almost identical reasoning to justify unauthorized use of abandonware to brand new games with caveats that mean you won't buy them. I'll skip expounding my personal opinion and instead concentrate on outlining a decision I think people need to make for themselves.
My first example is the most obvious example of nearly-abandoned-ware. I happen to know of a game that cost $20-$30 when it came out in
2001 and it now costs $77.48. Actually, it cost 75.00 CHF in 2001 and it still costs 75.00 CHF now but the exchange rate has made the game comically overpriced.
My second example is much farther down the slope. Spore was effectively abandonware to me while it was still in pre-release because its DRM meant I would never buy it.
It might be argued that my Spore determination at pre-release is insane because you believe that EA might have removed or changed the DRM to make it more acceptable but you're missing a couple things. One minor detail is that I've seen enough to know they wouldn't really change anything that really mattered. The major thing you are missing is that I get to decide whether I will buy something based on weighing the criteria I decide are important to me.
My final example is the one that I believe takes this concept too far. I've noticed one thing about many people playing games with an online component: a surprisingly large portion of the game public seems to think that video games need more penises so you can be sure at least one person will want to change the main character in the video game into their own penis and have the sidekick turned into Clint Eastwood's penis. I think a "YOUR PENIS HERE" game would be have to be a niche game designed for adolescent boys and the angry closeted republican LGBT crowd because you can't just fir that concept anywhere.