Why are some block constructors protected?

[CoffeeCatRailway]

Not sure if this is the right forum for this... just signed up!

Certain block constructors (eg. StairsBlock, TallGrassBlock, CakeBlock, etc.) are protected and prohibits me from doing new BLOCK_CLAZZ(PROPERTIES) when making a new block.
Just wanting to know if this is a mistake or not and if it's going to be fixed/changed.

[CoffeeCatRailway]

5 minutes ago, diesieben07 said:

Because Mojang made them that way. You can easily make a simple subclass.

True, I can make a subclass but it just wastes file space and is easier to just do 'new BlockETC()'