Well, "making art for hire" is not exactly the same as "being paid for your art".
The former is when you already have a buyer lined up before you start working. For example, a rich man in the Renaissance era might ask an artist to make him a sculpture of Bacchus fucking Ariadne. (You'd be surprised how many renowned artists were paid to make porn for rich folks.) In that case, the buyer might pay for the block of marble and cover the artist's expenses while he sculpts, in addition to paying him a handsome fee for his work. But then the buyer also has a direct influence on every aspect of the end product. If the buyer wants the girl in the sculpture to look like his underage mistress, it's going to happen even if the artist thinks it's a bad idea.
The latter is a broader concept, and it includes the case where you produce something first and then look for buyers. Novelists often work in this way, spending years to perfect their works without any buyer lined up. Some people who have no problem with this broader concept might still be uncomfortable about the narrower case of "making for hire", because of the direct influence that the buyer's spec has on the product. If you build it first and then look for buyers, at least you have a chance to show people that they might want to do things in a way they never even thought of before.
The former is when you already have a buyer lined up before you start working. For example, a rich man in the Renaissance era might ask an artist to make him a sculpture of Bacchus fucking Ariadne. (You'd be surprised how many renowned artists were paid to make porn for rich folks.) In that case, the buyer might pay for the block of marble and cover the artist's expenses while he sculpts, in addition to paying him a handsome fee for his work. But then the buyer also has a direct influence on every aspect of the end product. If the buyer wants the girl in the sculpture to look like his underage mistress, it's going to happen even if the artist thinks it's a bad idea.
The latter is a broader concept, and it includes the case where you produce something first and then look for buyers. Novelists often work in this way, spending years to perfect their works without any buyer lined up. Some people who have no problem with this broader concept might still be uncomfortable about the narrower case of "making for hire", because of the direct influence that the buyer's spec has on the product. If you build it first and then look for buyers, at least you have a chance to show people that they might want to do things in a way they never even thought of before.