Yes and No.
the Variables in soloQ is more random based then in GroupQ.
Example, I got nothing but Quiters, and trolls during my first 10 matches. It placed me in 935. Yesterday, I was in SoloQ where the other team had lost members, or had people in pve gear. this is the luck part.
in SoloQ it's not 4 vs 4, it's you vs 7 people. It's up to you to get better enough and fight against the odds. I played league of legends, and was stuck in bronze. Why? Because i didnt take the time and prepare myself for Rank. Sure i can blame the people who complained about not being able to Jungle or ADC, but SoloQ is 1vs9 people in LoL.
does it suck not getting a "Crystal" at 1000<? yes. it does. but theres always groups.