の and こと aren't interchangeable. But that's not the main point. I don't know how I should put it, but it seems the book's rule says sentences like "Xするには反対です" and "Xする、には反対です" are ungrammatical regardless of context because Xする can't be a purpose, i.e., it can't be "for," "in order to," and so on. But if Xする is, say, a political thing, I guess some people would use the の-less version to avoid giving the sense of の. 賛成する is also a verb that could be used without の because of the same reason, I think.
I googled for "するには反対です" and it seems almost all examples are sort of political or things that speakers don't want others to take it as "Xするのには反対です (implying "but I can agree with him in general," "but I agree with the other thing," etc)", e.g., 国歌を歌うように個人に強制するには反対ですが…, and 参政権などの特権を付与するには反対です。
Maybe this kind of sentence is considered wrong. Maybe the rare examples are all typos. But I kind of think they didn't use の because the ideas/thoughts they had in their minds didn't have the sense of の when they formed the sentences. They didn't compare anything in the sentences. I mean, they just wanted to say "I disagree with X," "I'm against doing X," etc. Of course, I wouldn't say these are better than the のには versions. But if those sentences are what they wanted to mean and make sense, I don't know if they should be considered wrong just because they don't follow typical patterns. Hmm. I don't know what "ungrammatical" means any more...
Anyway, I don't think there are many situations that make speakers want to say 人の性格を見抜くには長けている. I guess のには version is almost always better for almost all verbs/phrases when it's not about "purpose," though I only checked several common words for the verb+には+verb/phrase structure and typical situations.
I don't know if this is just 反対する/賛成する tend to be used in a situation where people make grammatical errors more frequently or this is a special usage of the verbs. Maybe those examples on the internet are all grammatical errors made by native speakers. But if so, it's kind of strange that certain verbs are more vulnerable to grammatical errors...
I googled for "するには反対です" and it seems almost all examples are sort of political or things that speakers don't want others to take it as "Xするのには反対です (implying "but I can agree with him in general," "but I agree with the other thing," etc)", e.g., 国歌を歌うように個人に強制するには反対ですが…, and 参政権などの特権を付与するには反対です。
Maybe this kind of sentence is considered wrong. Maybe the rare examples are all typos. But I kind of think they didn't use の because the ideas/thoughts they had in their minds didn't have the sense of の when they formed the sentences. They didn't compare anything in the sentences. I mean, they just wanted to say "I disagree with X," "I'm against doing X," etc. Of course, I wouldn't say these are better than the のには versions. But if those sentences are what they wanted to mean and make sense, I don't know if they should be considered wrong just because they don't follow typical patterns. Hmm. I don't know what "ungrammatical" means any more...
Anyway, I don't think there are many situations that make speakers want to say 人の性格を見抜くには長けている. I guess のには version is almost always better for almost all verbs/phrases when it's not about "purpose," though I only checked several common words for the verb+には+verb/phrase structure and typical situations.
I don't know if this is just 反対する/賛成する tend to be used in a situation where people make grammatical errors more frequently or this is a special usage of the verbs. Maybe those examples on the internet are all grammatical errors made by native speakers. But if so, it's kind of strange that certain verbs are more vulnerable to grammatical errors...
Edited: 2010-01-31, 10:25 am

Thanks a lot for the explanation and examples!