Were "Hitler mustaches" popular in nazi Germany? Did people try to impersonate the Führers looks or was this frowned upon? written by u/Georgy_K_Zhukov talks a bit about the possible motivations for the 'stache.

However, this question falls into the same challenges as do many, many other questions about Hitler, as written about in What was Hitlers reaction on Albert Einstein getting his American citizenship 1940? written by u/Georgy_K_Zhukov and On Adolf Hitler, great man theory, and asking better historical questions written by u/commiespaceinvader

The FAQ section "What did Hitler think about X" puts it very succinctly

For better or worse, many of these questions about what Hitler thought are, in the literal sense, unanswerable. We don't know what Hitler thought about many things, and especially about things which were inconsequential for him. Hitler did not keep a diary, and the collections of his private conversations is disjointed and nowhere near complete, being almost completely dependent on the post-war recollection of his intimates (who may also be unreliable in their recollections, especially given those circumstances).