Can you explain how its not?
It's pretty universally accepted that leasing isn't a financially wise move. It's main advantages are getting a late model car and updating it every 2 years, and not having to deal with maintenance issues.
It's obvious disadvantages without going into a full blown financial analysis is that you are paying money and not building any equity. If you pay $300 a month for 18 months, + $1,500 at signing, you've spent practically $7,000 for 1 1/2 years. Go get a new car for another 18 months etc, you've paid $14K for 3 years. $35K after 8 years. And at the end of all that you own nothing!
If however you buy a Brand new car for $35K, you are not limited on mileage use, and after 8 years you own the car which now has say 80K miles (to be comparable to leased), it's
KBB is approx $12,000.
Leasing -After 8 years spent $35K - left with nothing.
Buying - After 8 years spent $35K, left with a car worth $12K.
Of course it's fun to have a new car every 18 months, but know that it costs you $1,500 extra a year (12K/8 years).