With Shout! Factory releasing Super Sentai DVDs and non-Japanese fans getting the benefit of Tokusatsu with fan subs I want to think about another group of people. Some want to watch the subtitles because they want to learn Japanese. But others just watch subtitles because they might be the type to say, "I don't want a dubbed Super Sentai! I want to hear the real voices instead!" Then came Shout! Factory releasing Super Sentai but there's no sign that they may release more stuff.
So why are some non-Japanese Tokusatsu fans not so willing to learn to speak Japanese? I think these people are probably that weak with languages or real life is really getting into them. Just talk about the busy schedule people may have. One good example would be academics and the other is work. Maybe some of them are willing but real life affairs gets it out. They may have been initially willing to learn Japanese but end up not willing to learn it unless their job demands it.
There may be others who are still stuck with still learning at least one foreign language. Trying to juggle between several languages at once can be tiresome for some. Some people may quickly absorb them but not everyone can do it. Either way, I understand why some people are willing to read subtitles but don't have the intention to learn Japanese.