During WWII a lot of soldiers from the USSR died because of the incompetence of Red Army's generals. They sent lots of soldiers to die just like cannon fodder. Also in the Winter War against Finland the Red Army lost lots of men against a much inferior enemy numerically.
Yes, they certainly won against the best and biggest side of the Wehrmacht but I've always thought it was because Red Army sent hordes of soldiers.
Was the Red Army a good army or just a bunch of useless generals sending to die lots of people?
Consensus from experts seems to be: Yes, the Soviets were a great army albeit with a learning curve in the first 6 months of the war. Here are some great posts on the topic I could find that really help explain this:
/u/Ferrard gives an introduction level overview of Soviet grand strategy in the war and makes a solid defense against the casualty numbers. I would suggest looking here first for the answer to your question as it tackles it decisively.
This is also a good little post by /u/Fandorin Particularly his last paragraph:
The complete destruction of the Soviet officer corps in Stalin's purges had the most negative effect on the early war effort. The inability to coordinate attacks, counterattacks, organized retreats, encirclement breakouts, front-wide operations, effective use of strategic reserves - all the things that are achieved through experienced command structure and officer staffing - was responsible for the insane casualties. You can clearly see this improving steadily over the course of the war to the point when the Russian officers became as good, if not better, than their German counterparts.
A hard source I would recommend (that I'm currently diving into) is "Soviet Military Art: In Pursuit of Deep Battle" by David M. Glantz. It's a study from the U.S. military coming out of the Soviet Army Studies Office in Fort Leavenworth. Totally unbiased, totally unpoliticized military-sanctioned analysis of the Soviets and their capacity to wage war between '41 and '45 (and more importantly toward the end of the paper -- the capacity to wage war against the Western Allies after). I'm not nearly finished so I don't feel confident enough to speak generally about it yet but just from what I've completed I can tell you -- there is an element of healthy respect in the words I'm reading. The Soviet doctrine of Deep Battle was nothing to be trifled with once they grew into it in 1942/43.