You're right, bitcoin's deflationary nature means that present spending is more expensive than future spending. Therefore from an economic point of view it is not useful when it comes to stimulating an economy. Also similarly to gold there may come a time where bitcoin is steadily increasing but only at a slow rate, therefore there won't be such a trade off between present and future consumption.

There is also one thing that people always assume when stating that bitcoin value will always rise, and that's that demand will continue to increase. If demand remains static or falls then the price won't increase over time.