Sure, you can do things that don't constitute trespass. But unlike what's inside a store front, you can't observe the contents of a web server without interacting with it (trespassing).
Then what do you consider the storefront, or public facing data of a website? Just the whois info on the domain?
The general public can't observe the locked contents of a server without hacking it. Hacking is trespassing.
I would modify your analogy to say the store front is public facing, just like some of the LI data is public facing. There is other LI data that is not public facing.
In my opinion, websites have a larger storefront, as well as multiple levels of access to internal data.
The web isn't an abstraction, it's a network of privately owned servers responding to requests. This order tells a company that they can't program their servers to look at who is making the request and refuse to respond on that basis.
What is actually happening, is that somebody is walking into the store, asks a question about the stock or the price of the products on sale, which the store employee willingly answers.
Then, all of the sudden, the store wishes to control what you do with the answer that was willingly given to you.
This is clearly absurd - and so too is wanting to control what people do with publically-available HTTP data. If it's public, it's public.
I personally do feel that LinkedIn is within their full rights to attempt to detect and restrict content being served to screen-scraping agents, but they must then accept that screen-scraping agents must be allowed to use any means necessary to impersonate a "normal" user browsing the (public) information that they publish.
This can't be a one-sided freedom.