Should it be "aren't" instead?

Singapore is a multinational country with a wide variety of cuisines readily available to cater to different lifestyles and diet. “But many workers have not been able to adapt to the varied diet after spending 10 to 12 years in Singapore,” said Mr Chowdhury. With their work schedules, there just isn’t enough time and resources for them to try and adapt to new food, he explained.

Should it be "aren't" instead ?

Thanks.