your arguments are weak, you must not of played FO3 very much, it has lots of random encounters and events, tons of random patrols from all factions in FO3, raiders, mercs, hunters, slavers, outcast, enclave, wastelanders, new vegas doens't have any factions patrolling, and freedom of choice? you can do whatever you want in FO3, blow up megaton, kill everyone at rivet city, not help the slaves etc, so i'm not so sure what you're talking about, and the new vegas map is empty with almost no action at all, most people who bought NV it when it came out are already done with it cause they're bored, it doesn't even have very many good places to hide or stalk enemies, most of the factions live in tents..ncr, ceasers legion, the great khans, just sticking a load of tents all over the map isn't quality. the same 3 bark scorpions spawn in hidden valley if if you go by the area 100 times.
I played FO3, a lot, with like thousand hours in total.
In FO3, the only choice you have is whether a NPC live or dies; aside from to kill or not to kill, you made zero impact the Capital Wasteland.
There is no "random" patrol in FO3, there is just more spawn points; while in NV patrol actually start from their base and walk around their parameter. The only patrol in FO3 are the Caravans; Mercs, Hunters and wastelanders are all generated by "random" encounters, while Outcast is usually drag across DC because of their AI, and Enclave just sit around their outposts.
And FO3's spawn points is not even designed with character development in mind; FO3 is the one sticking spawn point all over the map, and THAT, is not quality. And yes, the same raiders always spawn at Super Dupermart, you just don't know if they would suddenly arm with a Firelance or Alien Blaster.