Xjyuk

In the Wikipedia article about lobbying in the U.S., I found this excerpt interesting:

The Lobbying Transparency and Accountability Act of 2006 (H.R. 4975)
legislation modified Senate rules, although some senators and a
coalition of good-government groups assailed the bill as being too
weak.

However, the linked source is no longer available, which makes it difficult to know why the law was deemed too weak.

Statement of Reform Groups on Lobbying Legislation Passed by Senate,
March 29, 2006. Campaign Legal Center, Common Cause, Democracy 21, the
League of Women Voters, Public Citizen and U.S. PIRG.

Can you explain to me why it was deemed too weak and what other countries do to make lobbying more transparent and less prone to corruption, and why the U.S. won't reform it to make it better for the people?

From the Internet Archive of the press release, which was issued by the Campaign Legal Center, Common Cause, Democracy 21, the League of Women Voters, Public Citizen, and U.S. PIR: (all emphasis mine)

A majority of Senators, for example, voted against the establishment of an Office of Public Integrity for the Senate. The Office was proposed to address the biggest ethics problem facing the institution, the absence of a publicly credible and publicly acceptable system for enforcing the Senate ethics rules.

The defense of the current system by Senate Ethics Committee Chairman George Voinovich (R-Ohio) came down to the public equivalent of "Trust us. We're doing a good job. We just can't tell you what we are doing."

That is not good enough for the American people.

Our organizations will continue to work for the establishment of an independent, impartial Office of Public Integrity in the Senate to help ensure that the Senate ethics rules are enforced.

The Senate lobbying bill also fails to provide any new restrictions on privately-funded travel for Members. The bill also fails to stop Members from treating corporate planes as their own private air force. The bill also fails to stop lobbyists from financing lavish parties for Members. These are all areas of great abuse that will now continue unabated.

The Senate lobbying bill also fails to require disclosure of numerous ways in which lobbyists provide financial help for Members, such as soliciting and bundling campaign contributions for Members, paying for Members' parties, making contributions to foundations and other entities controlled by Members and paying for Members' events, including conferences and retreats.

We recognize that the legislation does make improvements in a number of areas, including a ban of gifts from lobbyists, quarterly reports by lobbyists that are searchable on the Internet, disclosure for the first time of spending on grassroots lobbying activities, and disclosure for the first time of fundraisers held by lobbyists for Members and other federal candidates.

These positive features of the legislation, however, do not compensate for the greater failures of the Senate to address its most important lobbying and ethics problems.

My impression from the press release is that these groups did want this bill to pass despite the gaps in it, simply because it was a step in the right direction. Otherwise, they wouldn't have issued a press release decrying the Senate's failure to act.

It's deemed too weak because it leaves the revolving door open from Congress to lobbying.

As things stand, your career options after not getting elected are moving on, joining the executive branch of government in some form or shape, staying around as a lobbyist, or getting hired by one of your major donors for good services rendered. The two former aren't a problem. The latter two are.

There's chatter to disallow former congressmen from engaging in lobbying activities, or joining former major donor firms, if only for a cool down period. See for instance Warren's proposals on the topic.

If you need a primer on why it matters, see Lawrence Lessig's legal activist work (example).

Other countries suffer from similar types of issues. (One caveat: insofar as I'm aware, the US is the only democracy whose Supreme Court allows corporations to be full political participants.)