The whole practice is really detrimental to cryptocurrency. These aren't competing companies, they're open source projects.
This is true. However, most open source projects don't have value directly impregnated into them. Hence I can understand why some people might get overly emotional standing up for the coin that they had invested in. They don't want to see all of their hard work go down the drain in the event that their coin gets squashed by a competitor.
Sometimes trolling/fud is a form of coin tribalism, where people think that by knocking another coin, whatever they invested in will do better. Sometimes it's just part of the game... coin pumps, trolls come out to knock down price... be it because they don't want the coin to do well now that they sold, or they just want to buy back in at a lower rate.
Well said.