The reasons 1 by 1:

1) you don't need to edit HTML code to include scripts

The authors assert that you'd have do this by hand if you had a lot of static html. This is incorrect (you could easily insert the code using some script), but it also doesn't make sense, most larger sites (if not all these days) are dynamically constructed and adding a bit of .js is as easy as changing a footer.

2) scripts take additional time to load

This is true, but it only matters if you place your little bit of javascript in the wrong place on the page (say in the header). When positioned correctly it does not need to take more time to make the connection.

3) 'if website exists, log files exist too' (...)

This is really not always the case. Plenty of very high volume sites rely almost entirely on 3rd party analysis simply because storing and processing the logs becomes a major operation by itself.

4) 'server log files contain hits to all files, not just pages'

That's true, but for almost every practical purpose that I can think of that is a very good reason to use a tag based analysis tool rather than to go through your logs. The embedding argument the author makes is fairly easily taken care of by some cookie magic and / or a referrer check.

5) you can investigate and control bandwidth usage

Bot detection and blocking is a reason to spool your log files to a ramdisk and to analyze them in real time, to do it the next day is totally pointless. Interactive log analysis (such as the product sold by this company does) can help there, but a simple 50 line script will do the same thing just as well and can run in the background instead of requiring 'interaction'.

6) see 5

7) log files record all traffic, even if javascript is disabled

yes, but trust me on this one, almost everybody has javascript enabled these days because more and more of the web stops working if you don't have it. The biggest source of missing traffic is not people that have javascript turned off but bots.

8) you can find out about hacker attacks

True, but your sysadmin probably has a whole bunch of tools looking at the regular logs already to monitor this. Basically when all the 'regular' traffic is discarded from your logs the remainder is bots and bad guys. A real attack (such as a ddos) is actually going to work much better if you are writing log files because you're going to be writing all that totally useless logging information to the disk. Also, in my book a 'hacker' is going to go after other ports than port 80.

9) log files contain error information

This is very true, and should not be taken lightly, your server should log errors and you should poll those error logs periodically to make sure they're blank (or nearly so) in case you've got a problem on your site.

10) by using (a) log file analyzer, you don't give away your business data

well, you're not exactly giving away your business data, but the point is well taken. For most sites however the benefits of having access to fairly detailed site statistics in real time for $0 vs 'giving away of business data' is clearly in favor of giving away that data.

Google and plenty of others of course have their own agenda on what they do with 'your' data, but as long as they don't get too evil with it it looks like the number of sites that analyse via tags is going to continue to expand.