There's a lot of factors for lacrosse in order for it make it big IMO.
For starters, it's still a preppy white kid sport. I've played for years now, and I've played with the typical preppy douchebag who wears too much Patagonia and Vineyard Vines, has the flow, goes to some super duper preppy private school, and will buy his way straight through life because of his family's extreme wealth. And the sad thing is, that can apply to a lot of the lacrosse community. In order for it to grow, equipment needs to somehow be less expensive, as the sport itself is crazy expensive, and needs help reaching out to communities unfamiliar with lacrosse, not the Long Island-Pennsylvania-Baltimore areas.
Also, lacrosse itself is a hard sport to get any TV time. Obviously because it's still a less popular sport than others, but it's also harder to watch on TV. If you made someone sit down and watch lacrosse for the first time without them knowing anything, they'd have a rough time knowing where the ball is and how the sport goes. When you understand it, lacrosse can be a high intense, fun game to watch, but it's hard to make it marketable due to how small it is still. The MLL is barely competitive and pays its players very little (We're talking 10-20-30k here), the teams practice only usually once a week, nothing about it is serious. The NLL is even less well-paying, and although I actually prefer watching it to the MLL, you can barely find games to watch. College lacrosse is the only thing the sport's got going for them.
As I've mentioned, lacrosse needs to try and grow out and expand. It's doing a relatively good job at doing that, it's starting to sprout on the West Coast, Colorado, and Texas, Utah is getting an NCAA program, so it's improving, but there still needs to be a lot more work to it. US Lacrosse and other organizations really need to endorse the sport to farther out areas as opposed to just keep on feeding it to the same dominant areas.
It also doesn't help that every few years or so there is some big scandal that breaks involving some lacrosse team. The Duke lacrosse team rape scandal left a huge mark on the sport even if they weren't found guilty, the UVA player found who murdered his girlfriend also didn't help, and other smaller scandals that leave local imprints. It leaves a strong douche-y reputation on the sport.
(As you can tell, I'm very passionate about this lol)