Why do Auto technicians allow manufactures to set unrealistic warranty times?

The techs have no choice. It has nothing to do with "allowing". If Nissan/Renault wants to cut their warranty expense there is little anyone can do.

It is a shame labor unions have lost so much power. In some states if over half the techs want union representation the company must negotiate. I believe a petition has to be signed by people intrested in union representation. If the company gets wind of it before the petition is signed you probably would get fired. If you are intrested you may want to check with the UAW or even consider a different company. Good luck whatever your choice is.

I blame the unions,all the fighting over the years by certain big unions got what they wanted,money, benefits like a good pension,and when the other union members from different unions wanted to improve their wages benefits and working conditions,the big and powerful unions like the teamsters said to most of us GO FLY A KITE and slowly all unions suffered,and as you can see now some are going back to strong arm tactics,why because they know they have a socialist as president,and the president himself is using the unions for his benefit and his reelection.