I have to support the argument regarding the different metagame/environment.
When making an Ubers team, I think like I would in OU: Come up with a main focus, whether it be a weather focus, focus around one poke, heavy stall, etc; find pokemon to fit that main focus, make sure they synergize decently and don't overlap in terms of use and role; and find a suitable lead. Team building is generally all the same, and it's even easier (IMO) because now you can pick from ANY pokemon in the ENTIRE game (bar Arceus).
A team is built the same way, but I think what trips most people up is how to play them against other teams. What people fear most, it seems, is going up against another party of overpowered pokemon, where anyone could die at any given turn (offense vs. offense), or the battle could rage on for hours, even (heavy stall vs. heavy stall; happened to me once >_>). And because of the low popularity of the ladder, no one would want to wait 20 minutes to fight a battle lasting 2 minutes or 2 hours. It doesn't appeal, does it?
But I like diversity, and Ubers is a metagame that allows that. OU is SERIOUSLY centralized around Bulky Offense teams, as they work best in that environment filled with those kind of pokemon (Scizor, Metagross, Tyranitar, Machamp, all those TANKS). However, Ubers has no one solid type of team. A Heavy Sun stall team is as viable as a Heavy Offense Rain team; an anti-stall team is as viable as a semi-stall team; a bulky offense team is as viable as a balanced team. The diversity and slightly less centralized (in terms of overall TEAMS not pokemon (Kyogre)) Ubers metagame is what sells it the most IMO. From experience, I don't feel as though more 'skill' is involved, mind you I have no clue what people are talking about when they say 'skill' in pokemon. If skill refers to thought process, it's exactly the same: note down all the possibilities, pick out the most likely given the circumstances, act accordingly. If it's not that, I have 0% idea on what skill is.
Nonetheless, I also have another possible theory: are people afraid of Kyogre and the heavy hitters? Kyogre's got Rain + Specs + STAB + Water Spout from 438 SpA and a 100% accurate Thunder. Rayquaza has Dragon Dance, Swords Dance, Extremespeed, Outrage, Draco Meteor, Fire Blast, Earthquake, Waterfall, and all off of 438 Atk and Special Attack AND base 95 speed. I know you might say that the n00b would just use these guys, logically, but since they are inexperienced, they don't know when or where to send them out to get the set up, and who they are supposed to watch out for in the backseats (Lugia switch into +2 SD Rayquaza = lololol). But, then again, this all revolves around the fast-paced metagame and inexperience. To me.