After creating an objective, (let's call that objective "test_objective" for this example), and setting a score for a player, (let's use @p for this example), in /tellraw commands, that score is accessible which is expected. Example: 

/tellraw @p {"score":{"name":"@p","objective":"test_objective"}}

Prints the nearest player's score in test_objective to them.

However, this does not work properly when using it in the context of an item name or item lore. Example:

/give @p minecraft:fishing_rod{display:{Name:'{"score":{"name":"@p","objective":"test_objective"}}'}}

Should give the nearest player a fishing rod with that player's score as the name of the fishing rod however this does not work. A fishing rod with a blank name is given instead.