First, we should recognize that it was not actually Bilbo who said this, but rather it was part of the narration. The narration occasionally gives insight into the "true" nature of things, the distinction here being that this is how dwarves really are, and not just how Bilbo perceives them to be. Bilbo does share this impression, and has grown accustomed to the dwarves' nature at this point in the story.
Several things can be deduced from this quote;
- Dwarves are not all good or all bad; they are individuals
- Dwarves are generally more good than bad, but you must not push them too far
- Dwarves are concerned with money and risk
- Dwarves are not heroes
The question of what it means to be a hero is an interesting one, and reveals itself many times in the dwarves' action around Bilbo; they are very reluctant to risk themselves to help him, even though they know it is the right thing to do. Despite the fact that they are inspired to go on this quest to reclaim their birthright, they almost always shrink at signs of trouble, and Bilbo ends up doing the dirty work. In the moments preceding this quote, Bilbo is preparing to descend into the mountain to scout out whether the dragon is there, and anything else that he might see. The dwarves are, as ever, so apprehensive about the dragon that none of them volunteer; most scathing is Thorin's failure to go, when it is supposedly his kingship and his treasure that Bilbo is working for!
He did not expect a chorus of volunteers, so he was not disappointed. Fili and Kili looked uncomfortable and stood on one leg, but the others made no pretence of offering - except old Balin. the look-out man, who was rather fond the hobbit. He said he would come inside at least and perhaps a bit of the way too, really to call for help if necessary.