Is this worthwile to make published a short scientific essay, 1 page or less, that criticise the current trends or suggest a new research line? in which type of journals?
You are describing a letter to the editor. Most journals will accept these. But perhaps keep new research lines confidential for yourself for the future!
Most scientific journals have a section inside the journal for "brief communication". You could locate this section and observe the requirements of the journal considering this type of writing.