Yeah but that's on 10 different characters.
I just don't understand what there is left to do at 150 hours, I got to 90 hours at most on one of my characters and even then I had done most stuff around the Mojave.
It depends on how much time one is taking to craft stuff and forage for supplies for same. I have a number of characters who are played Survivalist-style, and they often take trips to the wilderness to gather more plant and animal materials to make foodstuffs and items for sale.
Some folks also spend an inordinate amount of time futzing around with the decor in their lodgings, or RPPing the armor type of their choice onto entire communities, or whatever else they like doing for hours on end, so it's not hard to see how he reached that amount of time on one character.
The most hours I have on one character is maybe 100, but that's because I keep restarting to test various settings and item values I keep fiddling with in the GECK. My latest character will probably exceed the 200-hour mark as he will play through all the DLCs and wander the entire wasteland, and he probably won't be the last to get there.
To give you an idea of how many times I've restarted: I have three active characters and 619 total hours played, and none of the current three have more than about 60 hours invested.