Occupational Therapy is a lot easier to get into as its not as popular as physio - Physiotherapy is very competitive and Occupational Therapy fairly unknown. When I tell people I am about to start at degree in OT they always ask 'what's that?'
There is also (apparently) a shortage of OTs, which may also be another reason for lower grade requirements to encourage people to take up the course.
However, it is still hard work, after receiving a reading list for the first year it demonstrates how much physiology/anatomy/psychology goes into the OT training - it does not look easy!
But, I was also once interested in physio but my biology was not up to scratch lol, after receiving a poor AS level grade in biology, I decided to think of another profession - I declared my E in biology on my UCAS form, and still managed to get offers for OT.