Michael Hudson's Insight

In his book, Junk Economics (2017: 292), Michael Hudson says that those 'conservatives' who narrowly define economics in terms of 'the market' and who also claim that there is no alternative to neoliberal capitalism (Margaret Thatcher's TINA) tend to 'take the existing social institutions [of capitalism] for granted' and hence 'not as objects of reform' - unlike 'the market' if it's not working as expected.

This is a fairly insightful comment of Hudson's. It tells us that while the official rationale for excluding the study of the social institutions of capitalism from 'economics proper' is because it's (apparently) irrelevant, that's not the real or only reason. It's because these 'conservatives' (a.k.a. neoliberal modern orthodox neoclassical economists) don't want the underlying social institutions of capitalism to be subjected to any theoretical analysis and consequently be the 'objects of reform'. In short, they don't want it to be a topic of economic and/or political discussion.

So, to avoid this, they simply push aside any critical examination of the underlying social institutions of capitalism by saying they 'take them for granted' - end of story! As a consequence, we're meant to take them at their word. But what exactly is 'it' that we're taking them at their word 'about'? Is it, for example, Marx's account of the underlying social structure of capitalism that they take for granted, which consists of a social power relation of production between the capitalist class and the class of wage-workers? Or is it a social relation between free and equal individuals in the market place? No one ever knows, as they never actually say what it is, specifically.

Perhaps, then, the best way to construe the mantra of 'we take the social institutions of capitalism for granted' is as a cover for avoiding any critical discussion about the topic itself.

If this is right, then we're in a better position to understand why they don't want 'economics proper' to be about anything else other than 'the market'. And, of course, it has the added advantage of suppressing any talk about the class structure of capitalism per se and what to possibly do about it, in general.

I should add here, that such 'conservatives' are engaging in (despite any protestations on their part) an ideological game to avoid any critical scrutiny of their type of 'economics proper'. And since this is the case, they are,  furthermore, not doing science; it's just bad faith.

Addendum

At length, Hudson (2017: 292) writes: 'Insisting that There Is No Alternative (TINA...), conservatives take the existing social institutions for granted, not as objects of reform.' And, in order to 'shift attention away from how markets favor... vested interests... , they exclude political power relationships as being... external to their economic models...'.