https://www.fire-magazine.com/building-regs-guidance-continues-confound-fire-sector-experts.aspx
Is it that hard?
If it is, what would you change to make it easier?
Blimey!
I remember when I first started using it - very daunting. But then we're talking about a document that has to give guidance on how to achieve acceptable fire safety in almost every different type of building you might choose to build (or alter) - how do you make that easy to follow for everyone who might wish to refer to it??? BS 9999 gives an alternative approach, but it's not necessarily 'easier' & it's still B1 - B5 at it's core.
Once you learn your way around it, & especially if you're a designer of buildings (rather than the systems themselves) so you use all of it - no, it isn't that hard & it's quite concise (in comparison NFPA 101 runs to over 500 pages, though it does include whole sections specific to particular types of premises - but you still have to refer back and forth to the 'general' stuff). Is it perfect? No, but if you required every guidance document to be perfect then none would ever get published!
I do wonder how many of these "experts" were people who actually use the guidance in its entirety as part of their day job, rather than people who just know the bits relevant to their own part of the fire industry & who would just like it to be tweaked so that it focusses more on their particular product?
Flexibility? If you don't like it use BS 9999; BS 7974, or there's not actually anything preventing you using NFPA, Australian, IBC or whatever you can find provided that you can demonstrate compliance with the Regulations themselves - how much more flexibility do you want!?