It doesn't seem to matter if you're making suggestions for someone else to implement or offering to do the work yourself; some people seem just as likely to sling mud at you either way.
So, you're offering to:
* Update the design specs
* Contact customers to get their sign off on the changes
* Update the developer documentation
* Update the customer facing documentation
* Translate that customer facing documentation (and any visible changes) into all supported languages
* Certify that your changes do not break any regulatory/legal requirements in all jurisdictions where the code will be deployed
* Develop all the changed code yourself
* Handle any merge issues with coworkers who were already altering that body of code
* Perform all QA regression testing to ensure your changes don't break any existing functionality
* Distribute and install the newer versions at all customer sites (who are willing to adopt your new version)
* Handle all incoming support calls for the customers who didn't actually understand/want your changes/that are having troubles with it
* Deal with the increase in support overhead/bugfixes for managing two versions of the code (before your changes and after your changes) until everyone is cut over to the new version
Are you starting to understand why "offering to do the work" is still going to result in adding burden to others that they don't appreciate?