Because more structural particles appeared, 专名号 is almost useless in current Chinese, but it is really useful in old Chinese as known as 文言文 because it is of help to 断句.

In modern Chinese, there are much more structural particles (such as"的""地""得") than those in old Chinese. It made 专名号 almost useless. For example:

（谢道韫）即公（谢安）大兄无奕（谢奕）女，左将军王凝之妻也。

——《世说新语·言语》

(This sentence means Xie Daoyun is the daughter of Xie An's eldest brother Xie Yi and the wife of General Wang Ningzhi.)

If we do not put 专名号 under 王凝之, the readers may think this sentence means Xie Daoyun is Wang Ning's wife(王凝/之妻, wrong 断句), not Wang Ningzhi's wife(王凝之/妻), because "之" also means "的".

But if we translate it into current Chinese, it will become:

谢道韫是谢安的长兄谢奕的女儿，左将军王凝之的妻子。

Since there are more "的", its meaning is clearer. Everybody can understand it.

In your example, "高尔基" is a foreign word. 译名用字 are very special in Mandarin. These words like "尔""斯""基""特" are not common in today's Chinese and when they are together, they can only form proper nouns. There is not "基体" in everyday Chinese, and students studying biology will not misunderstand it because they can 断句 correctly.