Mixing sprites is okay, but only to a degree. We don't want our sprites to look much like canon sprites, so scratching is a lot more preferrable to mixing. But I know: scratching an entire sprite isn't easy, so a little bit of mixing is inevitable. It has to be so that it is unrecognizable, so it takes a lot of effort.

Your sprite is especially obvious because of the way that the body flows together: the legs are at the wrong angle for the body which makes the waist unnaturally twisted, and the hat is sloped wrong for the head. It gives the sprite a really pieced-together look, which draws attention to the parts that are taken from other sprites. You also went with very recognizable pieces in the hat, arms and pants. You're getting a bad reaction because of this fact.

Take a look at this sprite of Alisa:

This is a mixed sprite with a few custom pieces, but it doesn't immediately look like it. Making small edit to the pieces, and being choosy with what pieces you use is essential. For example, I used arms from two different sprites, the face off of another, and the body from another. Then I pretty much drew the hair from scratch and coloured the clothes in how I needed them to be. One of the arms I used I'm sure someone might recognize, but it doesn't come off right away because of how it fits with the other parts, right?

TL;DR how to fix yours:
1. try finding legs that face the right direction for the body. Edit them if you can at least for colour.
2. Ditch your current head and hat. I can see the intention with the sunglasses, but they are not at the right perspective, and are very difficult to discern from the face, which then looks really squished. The hat is very obvious. If you can't scratch hair or a hat, do your best to edit something or use something that is less recognizable.
3. The blue that you've used is very bright, and the outline on the left side is not really there, while the outline on the right is very dark. Work on your shading as well as balancing your outline colours.