Why wasn't the BoS more in the mojave instead of just the bunker only dissapointment about the game

They lost a lot of Brotherhood guys at the battle of Helios One. Also I believe the only reason they were in the Mojave was because Elijah dragged them there. And the Brotherhood of Steel has been played out. They were THE main faction in two games. (excluding the burned game) It's nice to take a break from them.

Personally, I hope that the Brotherhood takes a backseat from now on. I loved them in New Vegas, you got to see an essential part of Fallout lore, but they weren't all in your face like Fallout 3.

Because Obsidian wanted to curtail the BoS and ensure that they weren't the major focus of another game. They wanted to show interaction between the three main factions, not more power-armord knights of yore.

The in-lore answer is that the Brotherhood is on the decline in the west and are dying off. They no longer have the numbers or the power they once did.

after looking back on the brotherhood they have become a shell of what they once were. I would like to see a Brotherhood chapter that openly recruits like the DC chapter does, as much as I disagree with Lyons, he is a Hell of a leader...

Check the Mid-West BOS. Sure they're fascist, have death camps, are basically a protection racket and use puppet leaders to gain control of towns, but they openly recruit/conscript. Even ghouls, super mutants, the former enemies not sent to labor camps, and even talking deathclaws.

And with all the info we get from Fallout 3 they are all but gone, so they are not a power they used to be.

I thought it said they were having tough times. For all we know that could mean the height of the Mutant Liberation Armies rebellion.

They were having tough times to the DC BOS which is at war with supermutants, Enclave and lost a fraction of itself to the Outcast, while only having one real base.

Veronica's quest really spells out the reason that the BoS is all but gone.