Everyone needs to be a bit more respectful starting immediately, or this thread will go the way it did on TO, as a lock.
There is a lot that both sides here are missing. I'm saying this from the perspective and knowledge of someone with two degrees in psychology and who works in the field of counseling.
1. A phobia is classified as an irrational fear of something, with the caveat that it is having a significant impact on their life due to the things they cannot engage in, or the lengths they go to avoid it. (note that this is not the definition as defined by Wikipedia, but it skirts around that). An intense fear of something that is not having a clinically significant impact on the person's life is likely to NOT be diagnosed as a phobia. This means that a few of spiders as appearing only in the video game Terraria is unlikely to be diagnosed as a phobia, if only because "can't play Terraria" is not a clinically significant impact on one's ability to live. However, it fits the diagnosis in all other ways.
2. A psychologist or counselor worthy of the name wouldn't be "giggling" about it, or laughing at them. They would take the issue seriously, and attempt to propose solutions to the situation, the same way they would address a real phobia, though they might express the point above (that it is not necessarily a significant hindrance). Don't use the threat of "psychologists laughing at you" as a way to demean people who are afraid of the spiders in the game. Its insulting to those who are afraid and its insulting to my profession.
3. While phobias are a serious issue, and not one to be taken lightly, there seems to be a misunderstanding about how they should be handled. In virtually no scenario would a counselor encourage a phobia to be avoided wholesale. One of the scientifically proven elements of phobia reactions is that the fear increases with each subsequent "avoidance" of the fear trigger. Meanwhile, regular exposure to it generally decreases the fear response. To everyone who legitimately has a phobia, not a fear (those who have a phobia can usually tell the difference), I would highly recommend seeking some sort of exposure therapy for it. Seeking to get a mod made to avoid it in the game . . . it will only make the phobia worse. I'm saying this in complete seriousness with many hundreds of hours of studying the subject. It is, of course, your choice what you do, but keep that in mind.
4. Everything else aside, expecting Relogic to change the game to remove the spiders is highly unlikely; if anything, the inclusive of spider content is rising with each update. Something to consider.
No more insults, no more disrespecting people's fears, no more belittling concerns. Discuss the issue, or that will be the end of it.