I have to admit that I never gave thought to GWB spending time with the troops after his presidency. It makes perfect sense, though, that he and Laura would do what they are doing. Being CIC was his favorite part of the job--of course he would want to greet his troops coming home or help raise money for them! We all know, being the man of honor that he is, that even though he believes he made the right decisions sending troops to war weighed/weighs heavily on him. I can't imagine what it is like for him to visit the wounded or comfort grieving families knowing that it was because of decisions he made their lives are forever changed.
I actually never thought about whether or not he would keep greeting troops or visiting the wounded (remember he was the ONLY CinC to go to Ft. Hood), but it's completely in character, isn't it?