I tell people I use AltText on my posts to aid visually impaired folks, as well as wider accessibility generally, and even to explain the meaning of the post in case it's not clear to everyone.
The truth is I do it because it allows me to be long winded and verbose twice in a post. Double bubble. Two for the price of one. Bonus blathering.
#AltText Don't deprive folks of your verbal diarrhoea!
