Three points:
1. The healthcare bill will likely be the bill that brings the country to financial ruin. We can't afford to maintain what we have now, let alone pay for a huge, new program. Even if you think this is otherwise a good program, is it fair to destroy your children's future over it?
2. Historically, the government has a bad track record running public services. Since there is no competition, there is no incentive to excel. While some on the low income side who couldn't afford it will receive healthcare, the overall quality of healthcare will drop. There will also be little incentive for major medical and pharmaceutical companies to innovate.
3. On the other side of things, just saying "no" to this bill is not enough. America needs healthcare reform, just not as presented in this bill. It's shameful for those opposing the bill not to provide alternatives.