This is clearly an epidemic
It is not clear to me that this is an epidemic.
If it were, these forums would be overwhelmed with similar complaints.
Swollen battery complaints DO get posted here from time-to-time, and they sometimes get reported here as swollen batteries or as trackpad malfunctions. The advice is each case is the same -- get the battery serviced (in whatever way you choose) so that it does not continue to cause you problems or become a dangerous issue.
Apple does not provide us the means to steer them toward "everybody" solutions. They continue to insist that THEY will tally the repair statistics and do the support and engineering required to determine when a problem requires massive intervention or warrants a recall.
When you have a problem like this (whether you know it is pervasive or not) the solutions available involve proceeding as if you are the only one experiencing this problem, and get it solved for yourself.
If you wish to be altruistic and tell Apple that you think this problem is pervasive, and suggest what they should do about it, you are free to use the Product Feedback links:
http://www.apple.com/feedback/
By definition, they will not reply.