I'm afraid this reflects a very narrow viewpoint.
Oops - quite the reverse was intended.
I can't speak to Tavistock specifics, but I have taken a significant look at my home town. There's a considerable number of sites on offer for development, some of which are far more suitable than others. Neighbourhood plans, and wider county and even national plans should be taken into account and where there's a supply of sites in excess of demand, an element of weight in the balancing decisions should be given to whether a development would block other things that might happen in the future.
I'm not going to put numbers to words like "might", "potential", "possible" and "probable", but I would look to joined up planning departments and specialists to take a balanced look at all the options and steer development in such as way that it's good for the community it'll serve, and for those passing through or past the community on longer journeys too.
Balance is difficult to write about in black and white - it's very much a grey area.