It gives you an out clause, for whatever reason, that cannot be disputed, and generally extends far beyond the Cooling Off period in timelength. With most land contracts you forego your right to the Cooling Off period if you get a solicitor to look at the contract so it is handy to have a way out if required.
You hope that it is not required to be used this way, but for all you know there could be some rediculous covenant or Council-imposed restriction that you don't find out about until its too late.
If I had of gone with your way of thinking I wouldn't have been able to buy in my estate.
If the bank tells me thy they'll loan me 600k, then borrowing 200k for land is not an issue. Seems to be common sense?
As I said, personal preference - it's not actually about the finance
If the estate in question doesn't play by my rules, then I'll find another block in another estate