Why does it say that they judged in Be'er Sheva?
Radak, Malbim: They did not go in Shmuel's way. He went around, so Yisrael would not need to toil to come to him. They stayed in the end of the land, like it says "mi'Dan v'Ad Be'er Sheva" (Shmuel 2:17:11). It would not be evil if they were at opposite ends. 1 However, both were at the same end, to make Yisrael toil to come to them, and increase their wages. 2
Malbim (1) implies that Shmuel could still judge, just he could not go around. Why did he not relocate to Dan? He was in Har Efrayim. We find that Shechem, in Efrayim, was in the middle of Eretz Yisrael from north to south (Makos 10a). Had he relocated, people in the middle of Eretz Yisrael would need to go far! (PF)
Shabbos 56a: It was to increase the wages of their Chazanim (who summons people to judgment) and scribes. Maharsha (56a) - had their Chazanim and scribes gone around with them, their expenses might have exceeded their wages. Also, perhaps they said that they are busy with matters of their city, and demanded extra wages. Bach (CM 9:8) - staying in Be'er Sheva increased the wages of their Sheluchim to summons people to Din [for they must travel further. How did this increase their scribes' wages? - PF].
