No, it doesn't.

You can apply to a new green card via the new employer (or any potential employer too). Once you get through to the I-140 stage of your second GC again - provided that the new job is one similar to your previous one - you can use your same place-in-line in the GC as before.

The green card application can get stuck in the bureaucratic backlog for any number of reasons - for years. These delays messes up with your peace of mind in ways you can probably imagine. Internet is full of horror stories about these things. This prevents people from changing jobs, or making any long term plans about buying a house etc.

It is a long-standing request from many people stuck in GC backlogs to not have them go through the _unpredictable_ re-application process, when they switch jobs. This was hinted as part of President Obama's Executive Action on immigration reform.

In a memo[1] dated 11/20/2014, Jeh Johnson (Secretary of Dept. of Homeland Security) stated:

  As you know, our employment-based immigration system is
  afflicted with extremely long waits for immigrant visas, or 
  "green cards," due to relatively low green card numerical limits 
  established by Congress 24 years ago in 1990.
  ...
  To correct this problem, I hereby direct USCIS to take several 
  steps to modernize and improve the immigrant visa process.

But USCIS has not done anything to improve this situation yet. There is currently a draft rule from USCIS titled "Retention of EB-1, EB-2 and EB-3 Immigrant Workers and Program Improvements Affecting High-Skilled Nonimmigrant Workers" [2] open for comments until Feb 29, 2016. I encourage everyone here to read and comment on this in the next few weeks. You can do it online by going to www.regulations.gov and searching for the eDocket number USCIS-2015-0008 [3].

[1] Executive Action: Support High-skilled Business and Workers - http://www.dhs.gov/sites/default/files/publications/14_1120_...

[2] USCIS Seeks Comments on Proposed Rule Affecting Certain Employment-Based Immigrant and Nonimmigrant Visa Programs - https://www.uscis.gov/news/uscis-seeks-comments-proposed-rul...

[3] http://www.regulations.gov/#!docketDetail;D=USCIS-2015-0008

Sure you "can" do a lot of things, but a green card application requires sponsorship - not something you can do unilaterally

Main problem with H1b is low wages and lack of mobility - lose your job and you're out.