Nissan Motors — Nissan micra size of spare tyre

Address:

680655

I purchased a Nissan Micra in 2013 from EVM Motors, Kochi. The car was registered in the name of Ms. Sylvania Niyas, my relative, at Tripumithura with Reg N0. KL 39 F 2777. The vehicle was transferred to my name at Thrissur in 2015.
On completion of 25000 KM one tyre was giving constant trouble by way of puncture. So I decided to change it & use the spare tyre.
To my surprise I found that all the four tyres are of the size. 15 inches radius, but the spare tyre is only 14 inches.I contacted the dealer, M/S Pinnacle Nissan, Thrissur, who informed me that it is the standard practice of company, that the spare tyre is meant to take you up to the next service point only.
Few questions:
World over why most Car Manufacturers are giving the identical tyre as Spare.
If you don't have a service point nearby will you not be risking the security & damaging all the other tyres.Since you insist on uniformity in all tyres, alignment, balancing etc
Te spare tyre since not used remains idle, gets brittle & peels off in 4-5 years.
It is a National waste that the unused tyre with full thread is thrown into garbage after 5-7 years.
What prevents NIssan from giving a standard tyre as Spare.