Of course it is. It's helpful for the people who've already bought into 37Signals' philosophy of doing business. For them, it's a reminder -- in-the-group signalling -- like a vaccination. If people nod and go, "Yeah! That's so true!" then they are confirming their group identity and commitment to the philosophy they've adopted.
If you're not thinking about these things all the time when you're reading things, you're not getting maximum usefulness out of them.
It's not just what people say, or what people read, but WHY.
