The main thing about lolita is not that you have to wear it all the time, but more that you have to follow certain aesthetics ( which isn't all that hard once you get used to the fashion. ) For example, you need to wear a petticoat to give it that distinct bell shape. Your dress should be made out of nice materials, and not costume satin, etc. If you change it TOO much, it ends up not looking like lolita at all. Its kind of like someone throwing on An outfit from Hollister, dying their hair black and trying to say they are dressing goth.
While I am sure there are some lolitas who think that everyone should be wearing a pink dress with a cute animal bag while wearing the same blonde twintail wig...Most of us enjoy and encourage variety in the fashion. (For example, wearing faux fur with lolita used to be seen as kind of tacky, but now it has become a rather popular trend. Some of the biggest brands are making fur capes/collars now. The fashion has changed quite a lot over the years, but the basics are still the same.