The reason classical liberalism looks better than contemporary liberalism is that it existed within a system of unspoken presumptions that kept freedom, tolerance and so on from becoming the operative final standards for the political system. The liberal standard of justice, equal freedom, had not yet forbidden public recognition of substantive goods like virtue and religion, which some people and parts of society take to more readily than others and so are hard to square in the long run with the liberal standard.
The effect was to liberalize the substantive goods—to let people hold to them in a more flexible and adaptable way—without destroying them. That was pleasant and seemed to realize the best of both worlds. That system lasted longest in the Anglo-Saxon countries. The inhabitants of those countries habitually ignore issues and refuse to draw conclusions, and as a result have routinely been accused of stupidity, hypocrisy, philistinism and so on. The accusations may have been true, but those qualities had their benefits. In the end though the logic of equal freedom conquered all—it was impossible to find anything to oppose it within liberalism—and led to what we have now.