Personally I agree on the patch programming, I've been playing computer games for 30 years (not continuously, I sleep every other leap year

) and the TS2010 patches were the absolute worst I've ever seen. They WILL work provided your system is clean and the disk is defragged and you don't have 14 million faulty assets installed when you try to patch it and you leave it alone - but the requirement for XP service pack 3 is ludicrous and the refusal to attempt patching after a single aborted patch is nuts. I've seen quite a few patches that check the main executable before installing, and refuse to install if it doesn't match the one they're looking for, but they invariably make a backup of that executable before starting and always at least make a valiant attempt to restore and clean up afterwards if the patch process fails or is aborted. This one is designed so you get one shot at the prize, if you miss you'll have to reinstall before trying again unless you made a manual backup.
Where I disagree is obvious, being a route developer rather than consumer I completely understand why route developers rarely even try to use nothing but built in content. Some of it just don't fit what you're trying to do, some of it just cramps your style - we are trying to create art here, after all.
Another consideration is FPS, I got a built in bridge that's 5700 polys and the route I'm doing needs one every half mile, there's a similar bridge on the DLS that's only 1400 polys which looks just as good - so the choice for the end user is a one time download versus not having to download anything and living with cruddy framerates, which would you rather have?
I limit myself to what is on the DLS and works error free in TS2010 native mode, and lately I'm testing occasionally in TS12 to make sure the end result will work for multiplayer, but it will require downloading some additional content for either version.
And I agree even with an FCT downloading all the dependencies and then having to download the dependencies of those dependencies it missed then having to commit all the assets it failed to automatically commit when it installed them is a PITA, but a PITA we just gotta live with.