The main problem with sending the Tour of Britain to being a REAL Tour of Britain is that a) most of the most interesting terrain is rather isolated, and the lack of knowledge of cycling in Britain means that few will trek to these isolated locations to see the few top level pros that show up, b) the way the race is funded means it's often loops or finishes quite close to one another funded by a county or city, meaning the transfers are already hideously long, and c) the rather engineered London crit finish (why not a circuit on the end of a trip in?) means you only really have seven stages to cover the whole of Britain, meaning in any given year lots of areas will get left out - especially given the tendency to use a few of the same areas (Blackpool, Stoke, Dartmoor) every year.
If you look at the route of races like the Tour of Poland, the Deutschlandtour and the Volta a Portugal, you'll notice that huge swathes of the country go ignored; it's just a general fact of dealing with short Tours around large countries; Portugal even has 11 days to go around a country far smaller than those with the Grand Tours, and is only covering half of itself this year. If England, Scotland and Wales were not separate entities, it wouldn't be so much of an issue, but the strong regional pride and national identity of the Scots and Welsh means that their absence from the race is noticed a lot more. I'm not saying that you don't have a right to complain (you do), but it's more clear than if, say, a citizen of Niedersachsen complains at the Deutschlandtour always missing their Land, or a citizen of Pomorskie complaining that their territory is always missed out from the Tour of Poland. This is the first time the East of England has hosted the Tour of Britain, but that's not so big a deal as it's only a region, not an actual country, so it's less a snub and more an omission.
It's also the case that a lot of the best terrain that could be used for a more challenging Tour of Britain is in Scotland and Wales, which makes it all the more easy to resent the Anglocentric approach.
However, another part of that is that there is precious little difficult racing in the national calendar. The biggest events are city centre crits and short course races. The Tour of Britain is eight stages, mostly flat. The national riders are geared up for flat races, and an eight day race taking in the sawtoothed terrain of a proper, good profile in Scotland, in parts of Wales and in the Lake District might be too much for them. There are precious few other stage races. A proper Tour of Scotland or Tour of Wales would be absolutely ideal - killing two birds with one stone in that it would give the riders experience of trickier stage racing, and allow the better terrain to be used. And then, with experience of setting races up in those areas they could make better cases to the ToB organisers.