If one wants a democracy, then citizens must have a right to petition and attempt to influence the government that is making laws for them. This includes individuals, unions (which also spend hundreds of millions on lobbying), religious groups (ditto), and business corporations.
Excluding some individuals or groups of individuals makes them second- or third-class citizens, and excluding all of them removes a major source of accountability from government.
The real lobbying fear is improper influence. That comes in two varieties. (1) Corrupt politicians who let the lobbying funds decide how they use their political power. (2) A previous political decision to let the government rule over area it should not be interfering with, which turns those areas into political footballs.