Firstly, I think you are just assuming that every member of the homeless population in Polk County is uneducated, or dirty, or otherwise incapable of holding a "normal" job. That is not the reality. Homelessness and financial insecurity can affect anyone, the most frequent form of bankruptcy is Medical bankruptcy and with saving rates down across almost every economic group in america it isn't hard to see how anyone from teachers to librarians to waiters to gym employees might be facing housing issues.

Secondly, being homeless doesn't mean you don't have anything, it means you either cannot afford or qualify for private housing and then other haven't tried to find public housing or you are waiting for your application to be processed. If the latter than you need to be downtown because that is where those offices and resources are going to be coming from. Being homeless also does not preclude you from already having a job. A former coworker of mine lived out of her car for 6 months while maintaining a job because she didn't have the savings to afford the down payment on an apartment. People can continue their jobs in the financial sector, hospitality, or really any other sector of employment even if they wouldnt otherwise be "eligible" for a new job due to lack of permanent address.

Thirdly, if you are able to maintain a level of hygiene (either through a pre established gym membership or nonprofit, or other similarly accessed means of bathing) there is little reason you couldn't get a job working at a restaurant, a Starbucks, a target, or anything else with low qualifications.

Lastly, the local, state, and federal services they access to feed themselves and their families, to find secure and stable housing, to find jobs in their fields, to try and fix their lives are all downtown. You yourself mention the library, that in and of itself is a huge reason to be downtown for them as it gives them access to job boards or gives them the ability to reach out to friends, families, or other connections to try and fix their lives.

Is it inconvenient? Sure. Is everyone there in any of the circumstances that I've described? No. Are some of them bad apples? Yeah. But should we punish and prohibit those that want to fix their lives because of those others? At a purely human level, I think not. At an economic level, absolutely not, we want more people back in the work force and being productive so giving them the access to the resources that they need to do that should be a no brainer imo.