Open load bearing wall
Yes, you can remove the 2x3 stud wall. 

There is 1) single top plate, 2) no plywood for shear wall construction, 3) no hold-downs for uplift or “racking” considerations, 4) the steel posts are close enough together to support 17 train locomotives (well, a significant load).

2x3’s are not used for structural walls. 

Is that an adjustable cap on that steel post?