While I do understand that this is a problem for some people, and mods can be a great way to solve it (although there only ever seem to be spider-replacement mods and not others of the same sort), I will point out that if you eliminate all animals that a significant number of people may have a phobic reaction to you won't have any animals left. Further, even though arachnophobia is more common than many, I don't consider it reasonable to take only one possible phobia into account when selecting creatures to put in the game.
I'm fairly severely cynophobic, and the Mabari in both games are easily realistic enough to give me issues. I find the one you end up with in Dragon Age II particularly terrifying for some reason, and that area in Redcliffe with all the Mabari jumping out at you is one I dread. I do think it would be unreasonable of me to ask not to have dogs in the game, however. I even try to use those opportunities to overcome my fear, but so far it hasn't worked very well. I still tend to wince away from the screen when there's a cutscene with the dog, for instance.
Ah yes our human race never stops to astound me. In most places around the world it is far more likely to get bitten by a dog than getting bitten by a spider (and in most regions geting bitten by a spider is pretty harmless as well unlike most dog bites) but yet arachnophobia is the most common phobia and people look at me as if I suggested to steal candy from small children if I say that I hate dogs.
Indeed. They are, in fact, dangerous animals. I'll admit that I'm afraid of even the ones that aren't dangerous at all, though I can usually manage to at least walk past those, but even a tiny dog can do a lot more harm to a person than your average jumping spider or cellar spider.
I don't even hate dogs, or dislike them as such (aside from panicking whenever I see them), I just wish people wouldn't take them everywhere with them, let them run around loose, and would frickin' warn me about them before I come over to their houses instead of warning me about the spider in a cage which can't even get out -- yeah, that actually happened. I'm cool with the spider, but they could've at least mentioned the dog, which I only found out about when it started rushing at the door and barking.
Is this not a joke? Phobia of digital pixelated spider? I'm acrophobia but i don't seem to have problem playing Assassin's Creed.
Different phobias tend to work differently, and individual people also react differently even within that. I believe that for phobias of things such as heights, open spaces, and closed spaces, it typically has something to do with actually physically being in that environment, so films and games aren't as often a problem -- or at least, most of the people I know which those phobias don't have a problem with films or games.
Phobias of various creatures, however, very often (perhaps even typically?) do get triggered by seeing images of that creature -- to a greater or lesser extent depending on the person in question and how severe their phobia is.