Why is the only check valve in Kitchen spray head in supply hose line bottom and not spring loaded?

[Anso G]

My condo builder installed American Standard Kitchen sink spray head stopped working today and identified the issue as:

A clogged check valve (a blockage of black grit and grease -- not sure what it is from, although we replaced the old water heater last year that was 9yrs old that had liner peeling)

The plastic check valve was placed in at the bottom end of the supply hose against the washer NOT in the spray head (which just has an empty space). It also wasn't spring loaded. The check valve is too wide to fit through the hose so it must have been installed there in the first place...

Any idea why this was placed there and not in the head? Does it even work there to prevent backflow if not spring loaded?

Thanks in advance!

(Image of where the clogged check valve was found)

 

[Geofd]

the ones I have worked on are always in that area why???? im guessing so the home owner doesn't take them out im sure if there was reverse flow the check would move to the other side from pressure