Here is a recap of the problems:
1)dio might not be kosher
2)according to bnei yona dio rapidograh is not dio
3)matyeg forgets to be mekadesh sheimos
4)metayeg makes jumbo tags that change tzuras haos
5)metayeg widens rashe hanun
6)metayeg who makes little mistake can easily do chok tochos or shelo kesidran to fix up
7)reb moshe showed how kutzo shel yud can get killed by metayeg.