Not everyone is just one personality or one value, so I don't think that there is anything wrong with identifying with more than one of your valued traits. I personally identify with Ravenclaw and Hufflepuff and have gotten both results on Pottermore.

I identify with both Gryffindor and Slytherin but it doesn't feel right calling myself a Slytherin (nothing wrong with Slytherin, I'm just not one), but that's why I call myself a Slytherdor if given the opportunity.

I haven't really thought much of them. It makes sense that people would come up with names to define the House mixtures they feel fit them, though.

I think they're a pretty cool idea. I used to think I was a Ravenpuff myself! Back when we were kids and I felt like I was a Hufflepuff although my brother and my friends all told me I was a Ravenclaw. Eventually (as the books continued and we learned more about the houses and the people in them) I realised that my brother and friends were probably right all along, and I definitely see myself as a full Ravenclaw these days. I do like Hufflepuff, but over time I've found that actually I don't particularly identify with the house.

But yeah, I think these hybrids are a cool idea for people who really do feel like they identify with more than one house.

(Personally, my favourite hybrid house name is "Slytherpuff" because I love how it sounds both sinister and cuddly all at once, haha.)