Because measuring temps using the Bios and other utilities is the most unreliable cloud chasing thing you can do!!
To quote an article I read about this:- "You shouldn't even ask what someone else's temps are. This is one of the biggest problems I see in forums. YOUR temps are not even accurate relative to your own system, much less someone else's.
Let me elaborate: Just because your board reads 41ºC, it does not mean that if the temps drop 5ºC in real life the board will read 36ºC. Motherboard temperature sensors are not "absolutely accurate", nor are they "relatively" accurate."
Trying to compare them to others rigs is just making the whole situation worse!
At best these temp monitors etc are just a point of reference useful for your own rig to, for example, compare how effective different coolers are or how different case fan configurations affect YOUR machine temps.
I used to do exactly what others and you are doing, which is ask what temps they're getting with similar rigs etc. There are so many factors that can impact on others temps - case, fans, ambient temps, bios version, near a window etc etc. All you end up doing is getting stressed and puzzled! And that's before you even factor in people lying about their temps... (They do you know...)
If your comp is stable, then what are you worrying about. These chips soon shut themselves down if they get too hot, and most temps I've seen reported (not that you can believe them of course!

) are well below that level, even under load.
And relax......