Single DIMM slot for HD4000? Seriously gimping DRAM bandwidth there. Most potential buyers probably wouldn't have minded the extra 3-5mm width for the 2nd DIMM and channel for double the max RAM bandwidth and total capacity.
that would actually be a nice desktop-solution for people like my parents. enough processing and graphics power for "internet"-stuff and video, quite user-servicable, efficient, hopefully not too loud, ssd+hdd...
Clearly you haven't used a haswell based cpu before. Despite having a lower claimed TDP they run generally hotter than IB cpus, and is likely the reason Zotac chose to use IB.
Haswell gets hotter than IB only under heavy load and the main reason for that is on-chip VRM.
Once you account for the part of motherboard VRM losses that are now on the CPU, total system power is roughly the same in most cases so the total heat that needs to get out of the box would be roughly the same.