Yes, this is a feature. I don't think non-immigration visas actually exist, or can in principle actually exist until there are massive legal and constitutional changes in the US up to and including ganking the birthright citizenship clause of the 14th amendment. Anyone who sets foot on US soil for any reason - even illegal immigrants, let alone people on a legal, ostensibly non-immigrant visa - can try to adjust their status, and has lots of "possibilities for appeal".

The US government should not give permission to anyone at all to set foot on US soil, unless the mass of existing citizens of the US are comfortable with that person eventually voting as a citizen on what the composition of the government should actually be. And as a US citizen, I am not comfortable with letting the vast majority of people in the world - many of whom are scrambling for any legal opportunity at all that will let them legally reside in the US - vote for the government that passes laws that affect me.