Usage guides have criticized dangling modifiers for generations, primarily because constructions that use dangling modifiers don't make sense when read literally as establishing a structural connection between the modifier and the nearest subject. Strunk & White, The Elements of Style, for example, addresses dangling modifiers in the last of its eleven "elementary rules of usage":
11. A participial phrase at the beginning of a sentence must refer to the grammatical subject.
...
Participial phrases preceded by a conjunction or by a preposition, nouns in apposition, adjectives, and adjective phrases come under the same rule if they begin the sentence.
[Relevant faulty example:] Without a friend to counsel him, the temptation proved irresistible.
[Relevant correct example:] Without a friend to counsel him, he found the temptation irresistible.
Few people deny that the initial impulse of a listener or reader is to associate a dangling modifier with the nearest following subject. Instead, critics of critics of dangling modifiers argue that in the real world speakers and writers use dangling modifiers all the time, and that in all but a very few instances their hearers or readers readily figure out the meaning that they are trying to convey. From these facts, the countercritics conclude that critics of dangling modifiers have greatly overstated the danger to communication that dangling modifiers pose.
But the question of how quickly a hearer or reader can identify the intended subject of a modifier is separable from the question of whether, at some level, a formally illogical juxtaposition requires correction. And if we accept that getting the sense of the sentence right depends on associating the modifier with its intended subject, it seems reasonable to ask whether that task properly and primarily belongs to the speaker/writer or to the hearer/reader.
I think that putting the burden of establishing accurate associations on the speaker/writer makes far more sense than putting it on the hearer/reader, if only as a matter of efficiency. If the author of an e-mail message structurally associates a modifier with its intended subject, then the message's five or twenty or one thousand recipients don't have to spend a tenth of a second or a half a second or five seconds each doing the job for the author.
Also, to the extent that dangling modifiers multiply and combine with other logical flaws in a speaker's or writer's discourse, they can have the cumulative effect of wearying and needlessly alienating listeners or readers. It's a bit like reading a question or answer on EL&U that uses nonstandard spelling or sloppy formatting: as a reader, you can make sense of what the writer is trying to say and yet still resent the person's slapdash approach.
Viewed from this perspective—which I suppose you could characterize as the perspective of a critic of critics of critics of dangling modifiers—the wording
As a web developer, I often help my friends with their websites when asked.
is superior to the wording
As a web developer, my friends often ask me for help with their websites.
Maintaining structural consistency also establishes a clarity of style that may sometimes be quite useful, as when you are dealing with more-confusable potential subjects of an opening modifier. If you consistently structure your sentences so that opening modifiers modify the nearest following subject, your readers can confidently interpret the sense of the sentence
As web developers, our friends often ask us for help with their websites.
as being that "our friends" are "web developers." If you don't, the meaning is hopelessly ambiguous.
