When I was android 17, it was a very good year
It was a very good year for small town girls
And soft summer nights
We'd hide from the lights
On the village green
When I was android 17
I'm still betting that he's being reintroduced just to have as a character of the main cast to be killed or have Xeno wipe - basically to be used to make an example of.
Goku only caring about the next big fight while all the other major players are fighting for their family would be a fun twist for a Dragon Ball story. It could even work for most of the other characters, Piccolo is pretty much a part of Gohan's family, Buu is fighting for Mr. Satan, and apparently Tien's recruitment will reveal
he running a dojo
.
Goku is going to be the only one fighting for himself out there.