Today it is possible to create a deal from a contact or a company workflow. But it is not possible to create a contact or a company from a deal workflow. Trying to automate as much as possible of our sales processes this sometimes accours to be an issue in my workflows.
You are free to create and set properties to deals, contacts, companies freely. So behind the scenes a lot of data can be created - copied - moved around the different properties. But to make things simple: In the contact properties there is a default property called "company name". Lets say a contact is created through a form and the contact himself fills in his/hers company name. Then it would be great if a workflow catched that and create a company based on the company name - and from there its possible to create tasks et cetera to continue. So - creating companies is therefor a obvious good thing.
I do lack some motivation to why contacts should be created by a workflow - but I found that anything is possible in hubspot doe to the flexibility in properties. So why restrict the great functions by not being able to create contacts from workflows. One example I can think of is that a deal is manually created by a sales representative - then from there I might want some basic things to simplify the representatives time by creating contacts based on properties in the deal.
At least give us the posibility and freedom to make the choice for ourselves.