I think (although I obviously can't speak for every doc) they usually see T2 as inevitably degenerative. And Gliclazide is on the list of drugs they gradually escalate through as the deterioration happens. Start with metformin, work systematically through to insulin. And it makes little difference (to them) how fast you get there, and how fast you burn out your beta cells...
On here, a lot of us take a different view, preferring to delay, or hopefully prevent that T2 degeneration - hence all the low carb discussions. The fewer carbs you eat, the less insulin you need, and the more you preserve those little cells.
The good thing about T2 is that you usually get to choose whether to fulfil the NHS expectation, or choose a different path.