In fact, I'm going to unabashedly vent a personal prejudice. No actual personal offence intended to any who disagree.
Quoting Michael Paoli (Michael.Paoli@cal.berkeley.edu):
And other random bits, like [...] using . to separate portions of phone number rather than -).
To me, writing 650.283.7902 instead of (650) 283-7902 would come across as either or both of:
o I'm hipster-trendy and ostentatiously display that, or o I'm too lazy to use the shift key.
The restaurants with all style and no substance all do the nnn.nnn.nnnn thing, in my experience, as do marketing people.
Now, admittedly, such things are mere cultural tribal-affinity signifiers and the underpinnings of Western civilisation are not actually at stake, but I personally am at some pains to put visible distance between me and those who're either (1) precious posers, (2) too lazy to use correct lettercase and punctuation, or both.
To me, I associate that entire style with the slobs who write mailing list posts in all-lowercase, i.e., disrespectful of readers.
Just My Opinion.<tm>