netmeg - 4:23 pm on May 25, 2012 (gmt 0)
Well first of all, I've yet to hear a reason WHY they would do it.
Second of all, if we're talking users who come to the site and immediately sod off, that's one thing. My bounce rates have never reflected that kind of traffic (except for bots).
But if we talking users who come in on normal keywords (to the extent we can discern from (not provided) + landing page) and actually browse the site, with multiple pageviews, maybe put one or two items in the shopping cart or maybe they don't - if they don't complete a transaction, that's on *me*, not Google.