Why would it matter to hitters if they can hit home runs? Scouts don't just look at how many HRs a guy has, they understand all of the variables, and so it should not affect how much they're worth if their HR production isn't as high at Safeco Field (I will always call it this because name changes are stupid). Plus, they can swing for base hits instead.
The only reason I can think of is glory and record books in the home run category. However, if that's what a player cares about instead of winning, then we shouldn't want them on the team anyway.