I might as well ask you the same thing. How would the other years have been different for the better without bonus seconds?
Obviously, in the grand scheme of things, it very rarely will have an influence but it's a nice detail to consider during the stages.
You don't like them of course because why would you...
It makes the racing more pure and simpler. It's very much an aesthetic quality.
When they are in play and matter, they distract. Then it's no longer about racing fast to the line or to distance your rival, and it makes a rider staying on your wheel much more annoying as he can wait to outsprint you on the line. And that leads to defending against being taken advantage of, just as we saw yesterday. I think Ax-3 in 2010 was different, as Schleck wasn't worried about any bonus seconds and not punished on the finish-line, so rather than both going slow it led to attacks as well, not just the timing of your sprint.
And sure, you like them because of course you do. Just like you like Valverde, rest days and short stages. Non-racing.