This is partially true. Economics originated in the field of political economy, which was at the time for lack of a better word, bourgeois. The political economists existed in a sense only to advise the government and monarchies on economic policy. When Marx set out to critique this field in his magnum opus which took thirty years of study to complete, Capital, he criticised them of obsessing over superficialities and only observing appearance rather than to drop down to the essences of capitalism.
In this sense, economics is inherently political and ideological, its anathema is Marxism which is a critique of this political and ideological field, but not a substitute of its own. It is not an economic theory, nor a political economic theory, it is a method of critique which is anti-ideological.
That was an awesome breakdown. I've never heard Marxism described quite that way...but frankly, the only things I've ever heard about Marxism are the absolutely ludicrous things said by the right and the stuff I've found on my own. Certainly not a great deal of exposure.
Reading Marx (or some explanation of his work from different point of view) is interesting. I think most of his critics do not apply to this world but he do have an interesting point of view and adding some of his ideas into your personal philosophy. I found really good critics of Marx from a rather liberal philosopher. I forgot his name, it was at my college library, but i'm pretty sure that if you are interested in philosophy and in economics theory you should read some of his work.
Part of the problem is that people tend to conflate Marx's approaches to history and economics with the (often conflicting) political parties and movements that claim to fulfill his predictions, referring to all of them as "Marxism". This is by no means limited to opponents of Marxism or socialism, since various groups are fond of claiming Marx's mantle for themselves.
Certainly the elevation of particular economists is largely political. This Yasha Levine piece on the creation of the Nobel Prize in economics is interesting and relates to your point (the short of it is it's not really a Nobel and was created to push a particular set of policies). https://www.alternet.org/economy/there-no-nobel-prize-econom...
