The issue for RK may have been the legal concept of "agency". As Brian worked for RK and offered support on this public forum, he probably legally was RK's agent and his comments could obligate RK, whether or not RK monitored his writing.
Agency may be the primary reason tractor manufacturers do not post on public forums.
A second reason is that corporate is more interested in the opinions of its dealers. I expect that RK is in regular contact with TYM sales and marketing. Once the price is beat down, TYM probably has little interest in spending more money supporting RK although most manufactures are interested in how retailers suggest improving the physical product.
A high proportion of tractor consumers here have an agenda of their own, many of which if addressed by RK directly would involve RK spending money on a brand (TYM) that RK does not own and could lose at the expiration of whatever term contract RK has with TYM.
During my working years I worked as an independent contractor providing sales services for California wineries, as a formally recognized agent. Pretty complicated relationships. The second winery eventually purchased my business and added me and my employees to the winery payroll, me as a direct employee at the VP level.