People think they have reasons to believe in God, and you cannot explain them away by attributing ulterior motives to those who accept those reasons. If you could do that, then a believer could say that the real reason people are atheists is because they don't want there to be a supreme being who can tell them what to do, or that they are engaged in activity that Christians regard as sinful, and they would have to stop it if they became believers. Or someone might be so afraid of wishful thinking that can't consider the reasons for being a believer.
The real question concerns the reasons people have for believing what they do. Whichever side is right, there is no shortage of ulterior motives to explain how someone might have ended up with the wrong answer. Arguments from motive really don't do much, because they are too easy for both sides to produce, and cancel each other out.