If anything, practicing yoga is about being yourself with less inhibition. It encourages open-minded acceptance of yourself and others. It encourages you to accept changes, challenges, limits and growth in life without suffering. It benefits the body, energy, emotions and mind all at once. It is about the middle path, sponteneity and developing an ever clearer view of reality and universal truth.
So just because the way other people express themselves under the influence of yoga turns you off or you have no desire to chant mantras doesn't mean that it won't benefit you. And in time, maybe you'll change your mind, or maybe not. Yoga is for anybody interested in highest health, happiness and the ending self-consciousness and uneeded suffering. You can be as "normal" as you want to be. But with your attention becoming stronger, you may very well notice that the need to fit in, and other habits become boring, annoying or are seen as unbeneficial and thus no longer useful to continue. Yoga helps you to discover who you really are, past all those conditioned responses and unconscious habits. From there you can know what makes you tick, how to be completely satisfied and happy in life. There's nothing "new-age", "superstitious", "wierd" or impractical about that. It sounds exciting to me!