People want closet space. If you fill it to the gills, the assumption is you don`t have enough closet space.
Remove the trophies, collectibles, knick-knacks and souvenirs so a buyer can imagine their stuff instead of yours.
And while you`re up there doing the windows, you might want to get up there and re-caulk.
If the garage is full of stuff, the seller is saying there`s no storage in this house.