Electronica has garnered a bad reputation as a word but it is about the only one-word term that can reasonably be used to cover all forms of electronic music, from Aphex Twin to Orbital, right down to mainstream production-line trance. The only alternative is to say "electronic music" a lot which is a bit of a mouthful at times, especially late at night, or to refer directly to the relevant sub-genre which can be tricky since there are so many now, some of which overlap (eg. Drum & bass and Jungle).
(I've got into many arguments before over the classification of my own music, about whether or not it was DnB or the other one, so I just refer to it as electronica now and hang the critics).
It's generally used to mean American techno and so understandably has come to be a by-word in the UK and elsewhere for half assed (as we see it) rave type noodlings.
For those of us who produce electronic music and thus have to use the term a hell of a lot, it's a word that should be reclaimed as soon as is humanly possible to prevent any more cases of soreness of the tongue.