I've said this before, but expansion to ease overcrowding is more important than improving coverage - both for Tesla's objectives, and for ours as drivers.
If an area has no coverage (parts of Wales, North of Scotland etc) then you know it in advance and can plan accordingly. If you believe an area has coverage, but you get there and find you can't charge due to congestion, then that's a big deal.
That's our perspective; Tesla's objective is to sell cars. Maybe they'll lose the odd sale to the customer who says "I spend my whole time driving the NC500, lack of superchargers up there is a dealbreaker", but for most customers it's either not an issue at all (based on where they drive) or one that can be talked through by the salesman and the concern alleviated. Stories in the Daily Express about road rage incidents at supercharger sites turn people off EVs before they've even entered the showroom, and linger in their minds even if it isn't an immediate deal killer.
So maintaining the existing coverrage under the increasing demand has to come first, expanding into new territories second.
That's aside from the more technical issues that shopping-centre sites serve a different user requirement from motorway service areas (drivers without home charging vs long distance travel), and the fact that many areas where it would be desirable to increase coverage are hard to do due to lack of power: if the DNO quotes a 2-year lead time for the new connection, it can't be built this year.
