I did let mine raise them the first year (starting 7 yrs ago). Then two years later after giving away a lot of roos, I bought silkie eggs on eBay and gave them to a hen who raised them up. Most times they'd cut them off at 8-10 weeks, but I had one mom who kept them until they were darned near adults.
We went on like this for a few years, but then I had to sell chicks, and pulling them away from mom seemed so mean. I let them keep just one a couple of times. Then the one who abandoned them at 6 weeks just to go be broody again just ticked me off.
I kept getting asked for chicks so bought an incubator and started hatching. That seemed so much easier. Now a few years later, it is just what we do, incubate, keep what we want, sell what we don't.