“The problem is not the amount of additional credit or interest paid, but the number of people affected.”

PS,
This in itself shows that U can’t use this argument against Credit Suisse’s statement. The statement says that the arm increase amount is small compared to net disposable income and hence would keep money flowing in the economy. Which is true. Whether this affects n% of people is not their concern.
Consumer spending demographics may change due to this but the economy as a whole might not be affected much. I’ve seen quite a few people who knew this long back and moved their investments in favour of this eventuality. It is up to you whether U see this and take advantage in your investments or be completely -ve about it.