If the kids are contributing financially and/or help in maintaining the household then it makes sense in this day and age.
Several years ago my son decided to get his Masters in data technology. Went part-time at work and moved back in with me. Cooked most of the meals, went to the store, took out the trash, kept his bedroom and bathroom clean and did his own laundry. Glad to have him back for a short time but he was glad when he finished and could move out, go back to work full time, and no longer have his bicycle stored in my living room. Win-win for everyone - but only because it was temporary! I love him dearly but as adults we both need our own space.
My kids often do the grocery shopping, and they pick up the cable bill.
And they both have good jobs.