I can't speak for @Lugia, but we often have similar points of view...
the main reason that it's often better to get a standalone drum machine as opposed to a modular one is expense - drum modules and modular drum kit synths etc and sequencing them is always going to be much more expensive, especially when you take into account case space, than a similarly functional standalone drum machine - most of which include both sequencing and drum kit oriented effects and are reasonably easily and cheaply synced to modular and often have way more channels for different drum sounds
this pretty much equally applies to everything related to percussion - with the exception, perhaps, of using more generic modules to generate drum sounds and either sampling them or recording track at a time in a daw or similar, this to some extent covers both modules such as plaits or peaks and rolling your own sounds from fundamental synthesis modules (vco, noise, vcf, etc etc)
take the quad drum for instance - it costs more than a cheap drum machine to start with, it needs to be put in a case, it needs sequencing, it doesn't have any effects, it needs to be fed into to a mixer and it's only 4 voices...
take say erica or wmd drum modules - you really want a few of them (probably at least 3) which adds up in cost very very quickly - and then you hit the same issues as with the quad drum...
take something like the queen of pentacles or blk_noir - mostly the same issues again - except mixing and effects are on board
the only advantages of modular percussion are convenience, "it's in the rack with everything else" and modulation - but you pay a major premium for that, generally many multiples of that for not necessarily that much gain...
saying that I have an in rack drum synthesizer (FSS Portland, which I DIYed), Peaks (which I often use for kick and snare), plaits (which I sometimes use for hats or other percussion), a general cv, a few lpgs and marbles, erica black sequencer and a zularic repetitor (which I often use for drum sequencing) and a befaco cv thing (again that I built) that I will use for sequencing my external midi drum synths - & I'd like (but not so much I'm running out to buy asap) a blck_noir and a crucible...
that's at least a couple of thousand in modules alone + at least a couple of hundred in case space (most of my 8 cases are DIY & under £1/hp) - when in all reality I could do 90%+ of what I use it for with a pretty basic and inexpensive drum machine... and get 90%+ the same results much quicker
at the end of the day it's your money... do what you want with it... find your workflow and make your peace with your money... no one cares, except you... take or leave advice as you see fit... etc etc etc
"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia
Utility modules are the dull polish that makes the shiny modules actually shine!!!
sound sources < sound modifiers < modulation sources < utilities