It may make sense depending on a person's particular circumstances, however there are many methods to access your funds prior to 59.5 and the worry about later expenses is relatively easy to account for. Accounting for later expenses rising due to medical costs can be done by increasing your withdrawal rate when you get older, generally with a 4% SWR it has been historically shown that you will have more growth than you will have withdrawal allowing you to increase your withdrawals when you get older. You can also mitigate that risk of expenses rising when you get older by exercising (more resilient to disease and the like), eating right (same as previous), flexing your frugality muscles (this gives you more fudge factor with your budgeting), and/or the most simple of the methods, account for the costs right in your FIRE number, as in save more money.
So since we know that the money can be accessed earlier than 59.5, you can FIRE earlier because of it, and there are several methods to mitigate a risk in increased expenses later in life there is no reason for ignoring the 401k in FIRE calculations. Just account for the risks you see.