I mean, he's got a point. Unfit, unathletic fat ****s can succeed at cricket. Athleticism certainly isn't as important in batting as it is in many sports.
I wouldn't agree that it's less of a "real sport" whatever that means, but it's defnitely a less athletic sport. Your physical attributes are way less important for success in cricket relative to most other popular sports.
Define athleticism.
A weightlifter and a marathon runner are both athletes, but very different athletes.
You absolutely require some degree of athletic ability to be a top level batsman - put aside reflexes and hand/eye coordination, the sheer stamina required to bat for hours on end is not something a powerlifter or sprinter will have. The power required to hit sixes is not something a marathon runner or yogi will have. The dexterity and flexibility to have good footwork and range of movement will not be found in an NFL linebacker.
When you start saying 'more' or 'less' athleticism - you need to now define athleticism within certain parameters and have a concrete way of evaluating it.
When people look at fat guys like Inzy and Ranatunga they think that anyone can pick up a bat and be an elite cricketer. But no one who has seriously attempted to play the game at a high level will agree with you here. It's just that cricket, for the longest time, paid no attention to the athletic requirements, whilst simultaneously appearing to the eye to be an easy laid back sport. It doesn't mean these men weren't athletes. You couldn't get off your couch and accomplish what they did even if we gifted you with the reflexes, hand eye coordination and technique to do it. Just go have a net session and bat for 2 hours and report back to us how you feel.
Similarly, go look up pictures of Roy Nelson, Mark Hunt and Daniel Cormier. And then look at their achievements, and tell me they aren't athletic just because they are fat.
Plenty of athletes in the NFL and MLB are overweight too. But somehow these sports are being held up as being far more athletically demanding than batting in cricket.