Meh, it's not more unreadable unless you have issues understanding || in the first place... and "or" is still a boolean operation.
Considering 99.9% of it's use in PHP is some variant of "connect() or die()", I stand by my statement. Besides, those "connect() or die()" expressions are widely considered bad-practice in the first place.
Also, using or instead or || for these types of things is more readable since it makes your intent of conditional code execution (as opposed to boolean evaluation) clear.