There is a nugget of truth in the advice to buy now while interest rates are low, but it has to be taken in context, and weighed against local conditions. There is a significant difference between buying a house and buying a used Honda. A car will never appreciate in value if it is being used, and will rarely appreciate, even if you carefully mothball it for decades. Houses and land on the other hand do appreciate in value during many periods.
There is something in the advice to "buy land, they're not making any more of it". That is, in the long term, growing populations and economies will force up land and housing prices. The trouble is that the cliche is only mostly true. Over the last 75 years house and land prices in San Francisco have been climbing steadily, with only brief (2-5 year) periods of decline. On the other hand, land in some neighborhoods of Detroit currently has zero or even negative value. That means, at least for now, it's a total loss of whatever you paid for it. If you buy land, you are making a bet on the future of the local economy.
So, if you think the local economy is going to grow, then the value of land is likely to appreciate, and it may be a sound investment. Obviously, buying land with a low interest loan is significantly cheaper than buying with a high interest loan. In the early 80s US mortgage rates were as high as 18%. Very few working folks could generate the cash flow needed to stay current with an interest rate like that. That brings up another caveat: there is no point in making an investment if you can't meet the terms of the investment.
Interest rates may be a bargain now, but land and house prices may be at the peak of a bubble. If your mortgage payment is so high that there is a substantial risk of defaulting, then it makes no sense to take the mortgage, no matter how low the interest rate.