I must agree it looks pretty bad right now, but this is Calgary. Today was the first day of spring and snowed. Nothing starts growing here until mid May if your lucky.
I assure you that grass does grow, also this is the "wallow" area. I agree the wall is rather garish. I feel that in the summer this enclosure, while on the small side, is effective and provides plenty of enrichment opportunities for the hogs. I have not seen the RRHs out but when warthogs lived in this enclosure, they always seemed to enjoy wallowing in the mud as most pigs do.