I think you are answering your own question when you point out a poor product market fit.
A good sales team will always struggle to sell a poor product. Customers today are pretty savvy, won't be hectored into buying as they once would, and certainly won't recommend poor product to friends.
The journey to good sales actually starts with decent market research, and key identification of who target customers are.
It's very easy to say all the above, but much harder work to actually do it. But once done, it makes the lives of sales teams much, much easier.
Find the great products, and sales will look after themselves, given even only fair management.