General aviation pilot reported receiving a terrain warning during approach to HND.

Narrative

I was descending for landing at Henderson Field (HND) from the east. I had studied the Las Vegas airspace and tried to prepare for the various shelves of the class B airspace. I knew there was a shelf at 4500 just north of the Boulder airport; so I flew south to avoid that area as I descended. With the sun low on the horizon; and in my eyes; I struggled to see the terrain in front of me. I was speaking with HND Tower and they told me to report a two mile right base for runway 35R. I was just clearing the last bit of significant terrain when tower advised me that the class B airspace extended down to 5000 feet in my location and that I needed to descend. At that moment; my terrain and obstacle display was instructing me to climb to avoid an obstacle. I had the obstacle in sight; so I elected to descend carefully. The tower did not instruct me to call them upon landing. In that location; there is terrain at 4601 feet and obstacles nearby at 5092 feet. I think an airspace restriction that keeps VFR aircraft below 5000 feet in this location is creating an unnecessary hazard. At a bare minimum; it must be teaching local pilots in this area to routinely disregard terrain warning safety systems.