The same reason we shouldn’t have gone to the moon in the 60’s, right? No practical reason, so why do it.
Oh, you mean we ended up finding all sorts of practical applications of the knowledge we obtained?
Nevermind.
There were many practical reasons why we should have gone to the Moon. If the US is to remain pre eminent in space we need an active space exploration program. Think battle stations in space with particle beam weapons. When the first operational battle station comes over the horizon, it better have the stars and stripes on it or the world will be cast into a dark age of at least 10.000 years.
The same reason we shouldn’t have gone to the moon in the 60’s, right? No practical reason, so why do it.
The practical reason for going to the moon was to secure our prieminence in space; or short answer, to command the high ground. The moon landing was mostly for show, but the space program is and always will be to own the commanding heights. Its all about winning wars.
Actually there is always a practical reason for manned exploration of whatever frontier there is. The nature of human life demands this.