I don't see why regulating the length of ads is silly at all. Several countries have been doing it for many decades. It works really well and has not led to any slippery slope, and made television much better overall. I have direct comparisons available from living in several countries during my lifetime--do you?
The slippery slope has been going down the opposite hill, actually, in America: It's amazing how much less rights a consumer has in the US compared to, again for example, in Germany.
The "well just don't do/consume/choose X then" argument is extremely shortsighted. If X is provided by commercial entities, then those commercial entities will, together, converge towards maximum profits with no regards for the consumer at all. Regulation is necessary as a counteractive force. A prime piece of evidence actually comes from your own post: "Don't watch the channel". Ok, I switched the channel on my cable box, now what? Ah, still the same.