I wouldnt compare bonds with REITS myself. The risks are very different and comparing the current returns isnt valid either
The thing about a good bond is that its top of the pecking order and so capital loss is almost a zero probablity (well maybe not quite ) They should be better than bricks and mortar - they should be rock solid. Hence low returns are acceptable for that part of the portfolio because its actually more about capital preservation.
I agree that growth should be held longer and more of it in the investment lifecycle nowadays due to increasing longevity and low nominal returns but for those who arent - shall we say - extremely comfortable- capital preservation can still be very important in the later stages.

We're actually offering a REIT of REITS at the moment (shameless plug)