Clinical, healthcare, and biomedical scientists (and clinical physiologists, please don't forget them) are absolutely necessary in the NHS, and I'm not sure what would make anyone think otherwise. In Scotland, our Clinical Physiology (Respiratory/Audiology/Sleep/Cardiac/GI/Neuro etc) teams take care of all sorts of testing ordered by doctors and other professionals.
These include ETT/EST (exercise tolerance, cardiac), PTNS (neuromodulation, GI), EMG (electromyography, neuro), NCS (nerve conduction, neuro), and a whole load more that I'm sure I wouldn't even understand. Some of these used to be done by other members of the medical team, but as patient numbers increased, it became unsustainable, leading to the creation of new roles and degree programmes. In Scotland, we have a specific BSc (Hons) Clinical Physiology programme at Glasgow Cal, which provides us with a chunk of the scientists we need. Additionally, we have ICBM and RCCP, the regulatory groups for Biomedical and Health Sciences, that gives us the registration for these wonderful people. Again, these roles have developed within the NHS into individual roles, now giving us scientists who specialise in reproductive medicine, infectious diseases, etc.
I'm no expert on the HCPC/RCCP/AHCS registered professions, as I only entered the NHS a few years ago, but what I do know is that if they all disappeared from the NHS, everything would fall apart; imagine an NHS without perfusion scientists, sleep physiologists, neurophysiologists, biomedical scientists. Say goodbye to proper diagnostics of neurological conditions, a heap of specific blood testing, sleep studies for OSA/CSA, and SO many other things; it would be a scramble to spread the jobs over to other people.
I'm not sure what your politician question means, since we do need politicians of some description to represent areas in parliament that otherwise wouldn't have a voice - again, I use Scotland as a reference; we have nearly 800 islands, split into different groups, and some seriously poverty-affected groups of people, who are all represented at a local level by our MSPs. Politics is interesting, and I admire people who enter the profession for the right reason. We unfortunately have a load of them who entered it for the wrong reasons, but until someone comes up with another plan, we're stuck with 'em.
Scientists need doctors, and doctors need scientists. My colleagues can't treat the patient alone; we need a whole range of professionals involved, from all sorts of different professions. So no, don't compare doctors and scientists, or their attitudes to each other. We all need each other, or nobody would get the help they need. We make the odd joke about how audiologists pretend not to hear their bleepers, or how the biomed students are actually the messiest group in the lab building, but we all need and support each other when we need it.