Interesting factoid - ukelele is the largest selling stringed instrument in the world by a long shot.
I find it curious Fender put the fret marker on the 10th and not the 9th. 10th is usually for instruments tuned in 5ths whereas ukes are tuned [generally] in 4ths that sees the fret marker at the 9th. A lot of peeps in the tenor/mandolin community were ticked when Fender released their Tenor Tele with the marker at the 9th - tenors are generally tuned in 5ths [but can be tuned any way you want].
I think it's a Ukulele thing and not a Fender thing. All my tenor and concert Ukuleles have a dot on the 10th fret.

