Depends on what degree of horror it is. If it's something like
"so i wuz goin 2 da mall n i saw dis shirt OMG it wuz da best!!! u wud love it"
then.. no. Just.. no. I know a lot of people who text like this and I don't complain to them, but if I were any more high-strung this would drive me crazy.
While a fully-texted out message with all words properly spelled is a beautiful gem to come across in a text message, simple, thoughtful and occasional abbreviations to save time and effort are appreciated as well. Either of the two above come across as a little more respectable, in my opinion.