When support needs are infrequent enough on the customer end, this effectively becomes a market for lemons--a customer can't know how good your support is until they've bought your product, and by then it's too late for them. People can advertise world-class customer support for one-time purchases because the few customers that encounter the awful support won't move the needle that much compared to shifting money from long term support teams to sales teams.

That being said, I realize this dynamic is likely much different for frequent/long-term buyers such as B2B solutions where quality support does translate to better retention and word-of-mouth advertising.