Id take a HR over a single everyday, it's just not practical to have every player on your team do that though (unless you are the Yankees lol). Great teams score when it matters and in the playoffs pitching goes way up and homeruns go down. Meaning the ability to score via a double and a single is magnified. Is it noticeable during a 162 game schedule....yes, but not as blatant imo. There is a reason at the end of last year we ended up where we did....last place in runs (AL) and dependent on the HR. Weren't we like 40%+ runs off the HR. I think we were most in the AL or 2nd most by far.
Also, I believe only 1 team ever has won the World Series and lead baseball in HRs (could be wrong on that but I thought I read that somewhere).
So, overall....HRs rule, but you have to score other ways to be great