what's so wrong about saying "my lawn is getting long/unkempt'???

this topic started because i asked "why would anybody do drugs if they could just mow a lawn" in my hank hill voice

i got into a twenty minute discord argument with two people telling me that it sounds funny and is incorrect. i looked up the definition and it defines a lawn as an area of mown grass. that, to me, means that the area IS grass.

nowhere in the google definition does it mention the dirt underneath it. they argue that dirt is included. they also say something like "the area doesn't get long." yes it does, right? if the area is the grass, and the grass gets longer, then that means the area of the grass also gets longer.

if you can say things like "my lawn is getting unkempt", untidy or even dastardly, then why not long? its another adjective

we start shouting and yelling, but i see no flaw with my statement and i'm willing to argue with them at any second.