Anyone! Of course anyone! It's not with the matter of language but it's beyond that. Of course, language is important but it is not the component of poetry. Poetry can survive without language. Language is just a medium by which poetry is expressed and language is very much needed and its not that language alone is needed. The perfect formation with words and a greater understandability is very much important rather than the figurative usage of words. People who never think of writing poetry is just because they are afraid of their language. A true poet does not take language as an important aspect. Poets those days weren't aware of some words and their spellings and their poems are literally wrong. But they are termed to be linguistic contributors, in the future. They were not afraid of their flaws but instead boldly said what they wished and also received an extra credit other than a poet.
Writing poetry Source: The Art Career Project
Poetry Topics Source: The Big English Blog
There's nothing as such worthy, instead there's everything that can be written as a poem. Even an ant's straight line path following a sugar crystal can also be written as a poem. Not every human sees the beauty in everything. He who sees so is no doubt, an artist. The whole world is rich in contents and they can easily be written as a poem. But the worthiness lies in the description and narration of the poem and not in seeing if the topic is worthy of unworthy to write on. Every poet for that reason would not blindly select topics and write for it. But it is for sure that everything that a poet writes would be worthy enough to read at least to a minimal audience.
A poet in action Source: wikiHow
A poet is not a human indeed, he's not born and grown but created eventually and are grown because of the appreciation he receives all around. One fine day, the rain clouds gathered all of a sudden and burst out a heavy downpour and there was a lonely Man sitting at a desk all wet and still not getting up despite the heavy rain. He could be a poet when he registers his reflections into words. A boss in a company giving advice too, could make a poet and this world has become so glorifying with too many more than necessary things that are not to be considered. But lucky are those who could find worthy poets who can write on worthy contents. As said before, none of the content with which the poetry could be written can never be unworthy. It is the poet's duty to make even the unworthy contents worthy.
The thought process of a poet would be definitely be very much active and that activeness is what could make a linkage between all the themes implemented in poetry. Not even every stanza, every line, why not every word and letter in a poem has numerous meanings.
Poetry a dope Source: Winc
If it's not necessary that a poet would write whatever comes to his mind some would be a long term thinking of the poet waiting for the right moment to escape his mind and become captivated with one word. Never a poet would get his poetry as desired. Satisfaction becomes an ultimate goal to a poet where it is not easily available.
There are poets who became completely blind on working for poetry. Many poets have gone mad and some among them never got alright but their contribution for poetry never stopped till their death. There may come many factors that could affect them personally. A poet is the one who's dedication and commitment would be at peak so that they never bother whatever happens to them, they will still be on their track. Only a few understand their responsibility and act accordingly. Not every poet would be that much conscious on whatever he does.
Frost in poets Source: Being Myself
Modernized poets nowadays rarely and never follow the classical rules with which the poetry were written in the classical times. Lyricists who write for a rap would have neither know how a classical poem would be nor would understand reading that. This doesn't mean he's to be degraded and the classical poet is the one who should be praised. Every poet has something which is very much urging in his mind and that would be what he needs to put in his writings.
Poetry Topic can be on anything. It would be mostly of the poet's choice and it would be a reflection of the society where he's living. The more the poet use natural reference in his poetry, the more aesthetic would be his work. A poem comes not with previously decided topic. The topic emerged as the poet's Central theme grows along with the poem.