A different question about Thestrals

[Eleanor]

No: HPFGUIDX 68393

At least, I hope it's a different question that hasn't been answered 
yet


What is the point, from the Hogwarts point of view, of keeping 
Thestrals?  Are they just there to pull the carriages twice a year?  
Because if so, why use winged horses at all (they don't need to fly) 
and why keep ones which are considered unlucky by wizards?  The first 
time a kid sees the Thestrals, they'll probably think they've gone 
crazy because no one else can see them; every time after that, 
they'll be reminded of the occasion when they saw someone die, which 
is hardly what you need on your first day back at school (on their 
very first day at school, of course, they don't see them because they 
travel by boat).  

It seems like there must be another use for Thestrals during the 
year.  If not, and they're just Hagrid's idea for another fun pet, 
someone should tell him it's really insensitive.   

Eleanor