The tropical Atlantic is covered by dust from the Sahara Desert, which keeps tropical disturbances from developing.
Barry was able to develop because it came off the land (which was odd but not unheard of) and therefore did not encounter the dry, dusty air in the lower- to mid-levels of the atmosphere over the ocean.
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In addition, over the Caribbean there are strong upper-level winds, which are unfavorable for tropical development.
The combination is keeping the tropics quiet, which is not unusual for the middle of July.