That is probably the fundamental flaw in the Ramsey teaching.
Historically (100+ years of data) investing in reasonable investments is going to yield a higher return than historical mortgage rates.
It all comes down to numbers. Pretty basic stuff. You look at the expected rate of return on your investments vs. your cost of capital. If you have credit card debt which has now skyrocketed up into the 20% range, you need to get that paid off ASAP at all costs. Ramsey's program is good for that.
If you have a locked in long term mortgage at sub 4%, don't be paying extra on that right now, you can invest in about anything to earn a higher return than that.
Every financial decision is simply a decision between risk and return.
Borrowing to purchase consumable goods (RV's, ATV's, etc.) should never been done on credit in my opinion. You can wait and pay cash for that stuff.