I don't think a prompt should be "use these five unrelated words in a poem". I do think that it's okay to pick random words from an impartial source or request words from random sources designed to stump the poet. The intention must never be to dictate meaning, story, or theme.
I've heard poets compared to architects, but architects don't work from whole cloth. There are architectural styles. Art Deco, colonial, Tudor, French Provincial, Bauhaus, all classic styles that architects take elements from and fuse them together into a wonderful cohesive thing. Architects don't operate in a vacuum. Architects must make allowances for terrain and environment. Prompts are just environmental factors that have to considered to build the poem.
I've turned sone odd prompts into poems I'm proud of. Among them are...
1: you turn on all the lights
2: the last time Frank did that somebody died
3: back when I lived in the secular world
4: the secret life of blue
I've written poems from every word played in a game of Scrabble.
I've had people give me three words and I've turned it into a villanelle.
My theory has always been the odder and more vague prompts lead to the most poignant end products. The poetry is in the personal interpretation of that which has been set before the artist.
I don't believe that a prompt should ever dictate form or function of a poem. It should not direct the meaning or theme of a poem.
If I give you the prompt " this cold cup of coffee", all I expect is for a reference to a cold cup of coffee, or how you perceive what that means in the context of your universe. The prompt does not even need to appear in the poem. It is a tool for focusing the gobbledygook in your brain into an arrangement of words on paper.
My respect for the obscure prompt comes from an open mic I used to attend. A sentence fragment was given to all readers before the show and the goal was to write a poem around/about/for the phrase on the paper.
It was a test for every writer in the room, and let's not be pretentious, poets are writers. We are not Einstein or Hawking. We are writers, and we filter the universe through our own senses ,our own emotions. We are working through a chosen medium. A medium that deals in self imposed rules.
Rules like numbers of syllables, stanza breaks, meter, repetition, and ,on occasion, a sentence fragment written on a piece of scrap paper handed to a poet at the beginning of an open mic.
As poets we accept which conditions to utilize and which to discard. We choose to write Haiku, Sestina, Villanelle, Sonnet or whatever. Prompts are part of the accepted conditions. There are poets who are good at prompt writing and others who are not, but writers need to write, and sometimes they need to write to uncomfortable conditions just to see if they can.
If we don't try to get out of our boxes by experimenting with new forms, we, as poets, become stagnant and irrelevant.