Clearly the Main quest did not give you the option on which side to say took over the Purifier, linear true but givin the option the quest would still have been linear just with 2 options at the end -> this time we get XXX options and they all are exactly the same garbage I did this and this and this for "Insert Faction Here" but everything I did was exactly the same -> you are forced to follow a single path around the game world so your compairing a single quest to an entire game in linearity FONV wins that race as the WHOLE DAMN GAME IS LINEAR.... from start to finish.
The only thing about New Vegas that is at all more linear than Fallout 3 that I can think of is the path to Vegas because of Deathclaws and cazadors. Even then, with a high sneak skill or just several tries you can make it past those areas. Also, once you level up, you can go pretty much wherever you please whenever you please. The main quest, though the objectives are similar for each path, is more open than Fallout 3 simply because you have a choice. Every other quest has several ways to complete it, which is, again, more open than Fallout 3. I don't see how New Vegas is any more linear than Fallout 3. Hell, that doesn't even matter, from the tone of your post, you simply don't like the game. To each their own.