For some of you it may sound like a strange question, however we feel obligated to address every question we have been asked.

Obviously we can’t deny the possibility that there are sentient beings suffering somewhere on other planets. But regardless of the chances, this cannot be a serious argument for the exploitation on this planet to go on.
All the current suffering on planet earth, and all the future suffering that would be condemned to continue by not destroying this planet, can’t be balanced with a chance that there are other life forms, and that these other life forms are sentient, and that they live on reachable planets, and that we would be able to somehow help them. It is statistically so unlikely that it seems more like an excuse. A way to feel morally o.k. with a very cruel decision - to leave this world as it is.

It is very ironic that activists, who are involved in relatively small scale campaigns in their local area alone, are raising the entire universe as a counter argument for putting an end to all the suffering humans are causing on this planet.

So far, here on earth, every year more animals endure more suffering. So seriously arguing that activists who so far haven’t managed to convince their own kind, who speak their language and share their social and cultural traits, to change their habits because it causes inconceivable suffering to sentient beings, would be able to do it with extraterrestrials?!
It took humanity more than 200,000 years to reach the point where less than 2% of it is vegan, and even veganism, the far better option, is a very cruel one. So how many more victims on this planet are required before humans would figure out how to detect, reach and help the exploited extraterrestrials?

Even if we go with this hypothetical scenario, it is very unlikely that activists are the first to be able to reach other planets and more likely it will happen only after humans have settled down there. In that case it is pretty obvious that humans would suck and squeeze everything they can out of those planets just as they do on this one.
If they are doing it to what is, as far as they know, their only possible home and the only possible home for their children, what reason is there to think that they won’t do the same on other planets if they got the chance?

If humans reach other planets, they would do the same as they always did, still do, and will never stop doing as long as we don’t stop them, they would destroy everything and everyone to serve their own interests, negligible and insignificant as they may be compared with the price others must pay for it.
Throughout history humans have exploited blacks, women, children, the impoverished, horses, donkeys, elephants, bears, pigs, sheeps, cows, fishes, chickens, everyone on this planet.
All of the above share genes with humans, as well as other significant features. A species that mass tortures and mass murders its relatively alike, and its own kind, won’t save but exploit beings from another planet.
It is far more likely that humans will experiment on the new beings or lock the "exotic creatures" in a zoo, or use them as living machines after finding the “best” way to “extract” the most out of each. And of course, occupy their planet and use its potential resources to satisfy more of their desires.

If there are sentient beings on other planets that humans could reach in the future, then humans will be their nightmare not their saviors.
So those who feel it’s a realistic option that humans would reach other planets which are inhabited with sentient beings, should be more motivated to end this world before humans could reach them too...