Increasing tomestone cap would cause more negatives than positives in terms of an active playerbase.

For those who feel they need to get now 900 a week it would only serve to burn them out quicker to the point where they may stop playing altogether.

It's much smarter to just accept that XIV will have a lull near the end of patch cycles. Just play another game and wait for the next patch to come out, all you're really asking for is more busy work to get more done even though a month from now there will be better gear to get.