Why the important things stay verbal
Proposals are written before the walkthrough or from a template afterwards, so the specific reassurances given while standing in the building rarely make it into the document. Nobody is being evasive; the conversation simply happens in one place and the document is produced in another. The consequence is that the commitments which most influenced your decision are the ones with no record behind them and the document reflects a general offering rather than your particular building.
It matters because people move on. The person who made the assurance may not be managing your site in a year, and their successor will work from the document. Capturing the verbal commitments turns them from a relationship into an arrangement, which is what you need when the relationship changes and nobody remembers the conversation in the car park and cannot be expected to honour a commitment they never heard about.
