Is modern capitalism inherently opposed to Buddhism?

Considering your quote, I would say your question is primarily about consumerism, in which case your initial interpretation is obviously correct: a way of life focused on the acquisition of material wealth and the consumption of sense-pleasures by the illusory "individual self" is obviously opposed to the Buddhist way of thinking, which rather aims to discard such attachments.

But since you decided to expand the actual question to "modern capitalism", I will refer to that as well:

Firstly, in its essence, capitalism (modern or not) promotes the individualization of capital ownership and usage/decision-making, based on the idea of "individuals" that can satisfy their desires better in separation than having to subject themselves (and their capital) to the desires of "others". It's an obviously ego-based worldview, clearly opposed to the Buddhist direction, which more closely resembles (doctrinal!) communism, where all capital is to be owned by everyone together and is to be put to use for the benefit of all, as it would be if administered by people who have realized the "ego" is illusory and that there is exactly zero difference between "my" interests and the interests of "others".

Secondly, modern capitalism is strongly intertwined with the idea of the free market (or competitive market), where individual capital owners compete against eachother to get as much as possible of the money the public is willing to spend on products and services. This is even more obviously an egotistical type of system, one that not only reinforces the illusory and detrimental notion of separate individual interests, it even explicitly pits these interests against eachother, maintaining an environment of unending competition/conflict, which is pretty much guaranteed to continually generate suffering in all those on the losing side of the conflict (and if we look at today's statistics on income inequality we can see that it's actually the greater part of humanity that's on the losing side at this time).

So I'd say modern capitalism is without a doubt opposed to Buddhist thinking because it's a fundamentally individualist and conflict-based system, and furthermore because of how tightly it's coupled with consumerism and the advertising/marketing machine that's keeping so many trapped in the sense-desire gratification cycle and implicitly in dogmatic ego-belief and in the cycle of suffering.

LE:
Since my interpretation was challenged in the comments I will add some supporting reference, and since Marxist thought didn't exist in the time of the suttas of course I will have to use more modern sources, in this case an article from the Access to Insight library:

The writings of some Buddhists from Sri Lanka, Burma and elsewhere offer interesting examples of attempts to relate Buddhism to nationalism and Marxism (not to be confused with communism). Earlier in the century Anagarika Dharmapala stressed the social teaching of the Buddha and its value in liberating people from materialistic preoccupations. U Nu, the eminent Burmese Buddhist statesman, argued that socialism follows naturally from the ethical and social teachings of the Buddha, and another Burmese leader, U Ba Swe, held that Marxism is relative truth, Buddhism absolute truth. This theme has been explored more recently in Trevor Ling's book "Buddha, Marx and God," (2nd ed., Macmillan, London 1979) and Michal Edwarde's "In the Blowing out of a Flame" (Allen & Unwin 1976). Both are stimulating and controversial books. E.F. Schumacher's celebrated book "Small is Beautiful" (Blond & Briggs, London 1973) has introduced what he terms "Buddhist economics" and its urgent relevance to the modern world to many thousand of non-Buddhists.

-- Buddhism and Social Action - An Exploration, by Ken Jones

To this I would only add that the author seems to be making the same distinction I emphasized above when I said "doctrinal Communism" by calling the doctrine Marxism instead, to distinguish it from all the historical complications and deviations of (nominally) Communist practice.

I agree with @ChrisW. In addition to his answer:

Here is a quote from the Sigalovada Sutta that supports investment in business.

The wise endowed with virtue Shine forth like a burning fire, Gathering wealth as bees do honey And heaping it up like an ant hill. Once wealth is accumulated, Family and household life may follow. By dividing wealth into four parts, True friendships are bound; One part should be enjoyed; Two parts invested in business; And the fourth set aside Against future misfortunes."

The Adiya Sutta discusses the five benefits that can be obtained from wealth.

The Dighajanu Sutta discusses how to maintain one's livelihood in tune:

"And what does it mean to maintain one's livelihood in tune? There is the case where a lay person, knowing the income and outflow of his wealth, maintains a livelihood in tune, neither a spendthrift nor a penny-pincher, [thinking], 'Thus will my income exceed my outflow, and my outflow will not exceed my income.' Just as when a weigher or his apprentice, when holding the scales, knows, 'It has tipped down so much or has tipped up so much,' in the same way, the lay person, knowing the income and outflow of his wealth, maintains a livelihood in tune, neither a spendthrift nor a penny-pincher, [thinking], 'Thus will my income exceed my outflow, and my outflow will not exceed my income.'

"These are the four drains on one's store of wealth: debauchery in sex; debauchery in drink; debauchery in gambling; and evil friendship, evil companionship, evil camaraderie. Just as if there were a great reservoir with four inlets and four drains, and a man were to close the inlets and open the drains, and the sky were not to pour down proper showers, the depletion of that great reservoir could be expected, not its increase.