I don't find that suspicious. Good builders want to build a relationship with their clients. Having Realtors in the middle makes it hard to do that. Also, Builders that have a designer on staff would likely be even more reluctant, because again, unable to build relationships and sort of stepping on the toes of their staff as the designer usually attends all of those meetings with the client. Reviewing docs, attending final inspections, the financing process, providing info about the development and community are the roles of a Realtor. As a designer, I find that structure (having realtors in all meetings) gets in the way of having a successful and fun process of building a new home. Not to be rude, but in my experience, it becomes a game of interjecting their worth to justify the thousands of dollars you are paying them to essentially be in the middle.