I don't see anything wrong with either of those.. The following are worse.
-socks + sandals
-socks + shorts
If you walk by the Jil Sander on Howard St. in NYC, the menswear mannequins right now are dressed in suits, with socks and sandals for footwear. It looks like Euro-tourist attire for the rich and tasteless.
Personally I don't think there is such a thing as a fashion taboo. One thing I've learned on this forum is somewhere/someplace there's someone who can pull off looking good by ignoring all the supposed rules. A taboo is nothing more than a perception conceived by an individual or group. What's taboo to one group or individual can and often is quite acceptable to another. Now with that all said and done does not mean that I'm not entitled to think that something looks like shit or is otherwise contrived. It's my opinion and it's just as valid as the next person's.