It's not about what you may think is easier or harder, it's about government overreach. Limiting the method you can get a legal product drives prices up because the competition is reduced. The government has no business telling me how I can get my legal products.
Once you open this door, where does it stop? Next, you'll only be able to buy tobacco at your local BATFE office, by appointment only, between the hours of 9 and 11, on Tuesday through Thursday. You may laugh at the extreme specificity of this example, but that's when I can get my concealed carry permit renewed by my local Sheriff's office. Once you let them change the rules, they won't stop until you have no right left.
And yes, I am anti-government overreach. "A government big enough to give you everything you want is a government big enough to take from you everything you have." - Gerald R. Ford