Their targeted customers are the political/public figure/corporate companies and such for Promotional project (a few pages of site, site for information/events etc), who needs relatively simple site but require certain hosting they can trust and rely.

Pretty sure, their are lots of demand from high profile people/companies who want to rely on WP.com to make their occasional/frequent needs for small to medium size projects, instead of contacting a WP VIP agency to cut some costs, for them $4900 starting point would allow them to cut some costs in the end.