[Svartalfiar]

Nevertheless, I’m not sure servers should specifically be singled out, among all other occupations, for income tax exemption.

Servers aren't the only ones that get tips. What we should do is eliminate the lower wage for tipped positions (ignoring arguments on minimum wage here), but treat tips the same way gifts are treated - tax-free up to a big amount. Tips aren't income, they're gifts.

[ansel12]

People tip workers that they know are receiving the tips as their wages.

Workers they see as being paid wages they don’t tip, no matter how helpful and self sacrificing, plenty of workers do more a heck of a lot more in service than serve food, but the lines of tips as pay are well known.