It is definitely true that creditors are tightening down. Without revealing my personal and household income, I currently hold the following cards:

Amex Plat: No set limit
Chase BA Visa: $25,000
Amex Blue: $22,000
Visa from my former university credit union: $8,000 (it's been stuck there for 2 years, after starting out at a lowly $1,000)
...and a few more.

When I applied for the SPG Amex under the 30,000 points promo, it only came back with a $5,000 limit, which is the lowest among all of my cards. I called Amex about it and they didn't really have an answer. I'm ok with it - doesn't really bother me, but it just underscores the point that credit card companies are tightening up - which is probably a good thing.