How many shirts do you own?
... and do you want to own that many wearable computers?
If this wearable technology really is built in to the sort of soft fabrics that people feel comfortable wearing for a day before washing them, then you will need a lot of wearable computers (or a daily cycle for washing your shirts).
And what about the fashion sense? People wear different types of clothes for different occasions. Are you going to have a few work/casual computers for the normal week, a few formal computers for meeting customers, some comfortable old t-shirt computers for the weekend and something hard-wearing for when you are out-and-about?
Sounds like a nightmare, and stupidly expensive.