「かみなりもん」 vs. 「らいもん」

Question

So I was watching something last year that involved a visit to 浅草神社. Along the way there were conversations over what was the preferred way to read the name for the temple—either using the kun readings (あさくさじんじゃ) or on readings (せんそうじ).

The next bit struck me as a bit odd, though, when they got on the topic of the temple's 雷門. I'd always assumed that it was straightforward: らいもん. As it turns out though, it appears that the proper name for it is a mixed kun-on reading of かみなりもん instead. Is there any particular reason for this?

Picture of the gate in question, for reference:

Answer 1

According to this article on Wikipedia, the name 雷門 first appeared in senryū (川柳) poetry of Edo period but it's not clear how it came to be used.

It's also interesting that the official name of the gate is full on-reading 風{ふう}雷{らい}神{じん}門{もん} and it comes from the two statues of Shinto gods 風神{ふうじん} and 雷神{らいじん} which stand inside the gate. The official name is written at the back of the lantern.