This is true, but he does have a point with the dungeons. In Skyrim they are very linear, even though i recall Oblivion's being almost just as linear.
He also has a point with the towns in Skyrim, they should have been more unique. However to compare them with the biggest cities in the previous games is unfair.
In Skyrim the dungeons are designed to have a different exit/fast way back to the beginning, that can make them linear but it's much better than running all the way back where you came from. The dungeons are also all hand made and much less repeating overall than Morrowinds/Oblivions dungeons.
The cities in Skyrim are smaller than in Oblivion or Morrowind, but they aren't unique enough? Have you ever been in Markarth, Riften, Whiterun and Solitude? They are all different, unlike all the other than capital cities in both Morrowind and Oblivion.
Leveldesing in Skyrim is probably it's strongest point, and suggesting otherwise makes me wonder if the OP is just trolling.