I started typing a reply yesterday, but it was already 3:30 am and my thoughts weren't exactly coherent, let alone my ability to explain them. Also I'll be damned if I know the answer since as most people I avoid Bot like the devil, so I'm just going to list a few of what I consider to be major problems. Bear in mind this is soloqueue, with an experienced team who is communicating through skype or what have you the situation changes a bit, unfortunately from what I've seen not nearly enough.
So first have a glimpse at this statistically irrelevant sample of six games I just played [team presence is the first time a member of that team appears bot] :
Someone else Champion Champion Team Presence Team Presence Number of Ganks Number of Ganks Game Won/Lost Notes
going bot Blue Purple Blue Purple Blue Purple
No Diana[me] Jax 04:06 05:45 1 gank 7 ganks lost I won lane until ganks
Switch - Zyra recap gank
Yes Zed [us] Talon 10:55 02:54 1 gank 1 gank won Lane was even bot
I could, but Shaco Zyra[me] 05:00 07:05 4 ganks 2 ganks lost Top failed hard
rather not Switch-Ryze Switch-Blitz gank cap
I could Diana Irelia[me] 11:20 12:45 3 ganks 2 ganks won Destroyed bot, farmed at their health relic
gank gank
I could Syndra[us] Jax 05:36 06:00 lost
I could Kayle[me] Teemo 05:53 05:44 lost Afk on my team, constant 2v1 bot, I won lane before the 1v2
This is completely neglectable as a sample, but from my 1200+ games on Dominion, the general trend is the same : unless top or bot fails hard, bot remains isolated.
Problems!
1. It's isolated : as I already said, in solo play, more than anything else in league of legends, bottom lane in Dominion is its own universe, which will only see action in the first five or more minutes if top gets completely smashed for either side. The time between ganks is even greater, considering the average game lasts 20 minutes. There are champions whose role revolves entirely around ganks [Rengar, Khazix, Evelyn] and if you have good players you can completely mess up the other team, forcing constant switching and drawing defenders from other points, but at and below average level soloqueue it's a crapshoot. I've gotten entire games without a single gank bot.
2. It's incredibly important : Bot lane is the best point of pressure on the entire map. Top can be fortified with the proper teamcomp/simply Heimerdinger, and while bot and mid are the same distance from the Nexus, you already have a person bot. Mid is way too close to the enemy nexus to allow anything more than a brief backcap/point swap. This does mean your entire team and every person in it need to be flexible in their positioning and possess great map awareness. Taking off defenders from top only counts if you can either hold the point you just stole, or quickly exchange it for another one. Bot is generally easier to hold because you already have a player there who is, ideally, ahead of his opponent.
3. It's about pushing : unlike lanes in SR where the main goal is to farm minions and maybe kill the other guy if he dun goofed - unless you have a strategy revolving around pushing towers quickly and laneswapping [and let's face it, unless you're a tournament player, you don't], bot lane is about controlling the health pickup, sustaining in lane and shoving the bastard way up the other dude's point. Since Dom is a capture-and-hold affair, capturing or at least dropping the point neutral is a great boon. However, like SR, when you're pushed all the way to the enemy point, you're really easy to gank. These two things lead to people overcommitting, dying, forcing a defender from top to go bot and recap and a vicious cycle.
4. It's boring : while top is either a tense skillshot-standoff or a completely bonkers 4v4 divefest, bot often devolves into a farming session, especially with a lot of the semi-top tier picks - Nasus, Nunu, Malzahar/Heimerdinger, Singed, two AD carries, two AP carries. Even more common is the situation I got to in my Irelia game listed above : I can kill the enemy bot, but not really dive them at tower, and our clear is the same. This leads to a situation where I clear the wave at its spawn point, they clear my wave on their point, and we wait for the next one. This means not a lot of people are actually willing to go bot and you end up with a lot of "ehhh... I guess I don't really care where I go". It's somewhat rare to get a player willing to play bot and it's even rarer to get a player who actually knows what to do bot.
The way I see it bot lane needs a greater degree of integration. Dominion is a lot more team-oriented than SR in that you need good teamwork to win - you can't do well in your lane and carry a Dominion game, and there isn't a position like jungle which can affect the entire game. There are far more opportunities for entering a teamfight from the sides and behind, and there doesn't actually exist a situation in which you're safe. You can always be dived and gibbed, unless you have 2 disruptors - Alistar, Amumu and the like. This is why ad carries on Dominion are not very good - a full bruiser team is at an advantage if built correctly. And bot lane is about staying in lane, pushing the lane, going back and shopping. It's not even about fighting the other dude, it's about staying safe and pushing unless you're jax/fiora.
Toying around with the length of the lane, the layout of the jungle above it, the distance between mid and bot, the pickups, the size of creep spawns and the like would possibly have a beneficial effect on it and make playing there more involving, but as long as the map itself focuses on constant teamfighting, and bot focuses on idle pushing and never leaving your lane, the two will be at odds.