Or, perhaps someone has a moral reductionism in mind during a particular use of 'ought' language. Perhaps by "You ought to be more forgiving" they really mean "If you are more forgiving, this is likely to increase the amount of pleasure in the world."

As you can see, it is not hard to bridge the is-ought gap.

I don't think it is impossible, but it is harder than you are making out. The examples given are not complete syllogisms, or other logical forms. It is easy to validly derive an ought form an is: you start with the factual statement and then invoke a bridging principle of the form:

if <is statement> then <ought statement>

However, the argument is not sound unless the bridging statement is true. But the bridging statement is itself an derivation of an ought from an is, so there is a kind of circularity there. You are assuming that the ought-from-is problem has been solved in order to solve it.

As I said, I don't think the situation is hopeless. The bridging premise is not exactly the same thing as a moral argument: it is usually more of a general statement along the lines of "if X increases well being, it should be done". That provides some scope for an analytical justification of bridging principles.