Has it occurred to you that I am not so much looking down my nose at the professionals as I am at the prevailing television practices of the time?
I think that Graeme Harper is a wonderfully talented director, for instance, and he worked on the original Doctor Who. I also happen to think that the kinds of cinematography practiced on the original series was creatively stifling and hurt the material. Television is a visual art, and I don't approve of practices that stifle the ability of its artists to fully develop the medium. I would not be the least bit surprised if the people who worked on the original Doctor Who would have greatly preferred a larger budget and more sophisticated cinematography.
Interesting point actually, the answer for which you need to go right back to the beginnings of TV in the UK and the USA.
Put simply, British television, in particular the BBC, comes from a theatrical background. With small budgets, live and later videotaped drama were common-place. They were rehearsed with the cast and the director, much like any rep company, and then run through as a play, or later as live, with each scene in order. This continued right through until the late sixties and early seventies. Consequently you had directors, lighting supervisors and set designers all continuing from their theatrical training, but performing in front of a camera rather than an audience. Then you had issues like the BBC chiefs demanding that programmes be well-lit to avoid people thinking their televisions were malfunctioning - a genuine concern.
On the other hand, as I understand it, American drama all came from a film background. It was made in Hollywood, produced on 35mm, using all the techniques and practices learnt from the movie industry. There was also a lot more money thrown at it. In the UK there were filmed, cinematic series, but these tended to be the exception, and often had US co-funding - The Avengers for example.
It's only really in the eighties and nineties that British drama tries to be more overtly cinematic rather than theatrical, and that's to do with the way the BBC changed at that time. There was more outsourcing, and less drama made in-house at Television Centre. You had a new crop of creative people who had grown up with television and film as their main (or sole) frame of reference, rather than theatre.
Audience expectations were also increasing, thanks to the flood of US series on our screens. Let's not forget that one of the reasons Doctor Who was dropped was because it was looking pathetic in comparison to the latest American import - Star Trek: The Next Generation. A long process of seeking US-backing for a new film and series ensued...
So it's not quite as simple as saying if they had more money, they would have done it differently. It's as much a part of the culture and prevailing tastes and trends as it is the budget.