It's not on public property. The sign(s) are part of a group of small business signs for a strip mall. Clearly, they aren't intended to solicit any business from a non-Arabic speaker. The Kearny Mesa area has lots of Chinese, Vietnamese and Korean merchants. They label in their native language AND English. There are parts of town with Spanish only signs, but that is somewhat expected with the large Mexican-American population.
O.k. Then it is not as bad as I thought. We don't want English-speaking American folks doing business with them anyway. ;)
*shrug* I can go a few blocks and see signs in Vietnamese with no subtitles.
Withing a few miles, I can see monolingual signs in English, Spanish, Vietnamese, Korean, Chinese, Ethiopian, Hindi, Arabic, Japanese, and a few I don't even recognize!